Abstract:
A plasma display panel (PDP) is capable of effectively reducing noise occurring during operation of the panel by improving the construction of a dummy partition included in a partition, and reduces a rate of defects in the partition due to a uniform coating of a fluorescent paste. The PDP includes: a front glass including sustain electrodes and dielectric layers; a rear glass including address electrodes and dielectric layers; a partition between the front and rear glasses and including a main partition and a dummy partition, each having discharge spaces of respective sizes; and a fluorescent layer coated on the respective discharge spaces.

Description:
CLAIM OF PRIORITY 
       [0001]    This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from an application for PLASMA DISPLAY PANEL earlier filed in the Korean Intellectual Property Office on the 6 th  of Dec. 2006 and there duly assigned Serial No. 10-2006-0123181. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to a plasma display panel and, more particularly, to a plasma display panel which increases productivity and product yield by improving an arrangement of a dummy partition wall included in a partition wall. 
         [0004]    2. Related Art 
         [0005]    In general, a plasma display panel (referred to as ‘PDP’ hereinafter) is a type of emitting device which displays color images using a gas discharge phenomenon in each cell. Since the PDP has a simple manufacturing process, high response speed, and a large-area screen, it is highlighted as an image display device. 
         [0006]    The PDPs are classified into direct current (DC) and alternating current (AC) PDPs depending on driving waveform shapes and discharge cell structures. 
         [0007]    Additionally, PDPs may be classified into facing and surface discharge PDPs depending on the arrangement of electrodes. 
         [0008]    Among them, AC PDPs are a means to a display color image using a three electrode arrangement, and they have a construction that forms a partition in a panel, and an interior of the partition is coated with a fluorescent paste so that a fluorescent material emits light according to a power supply. 
         [0009]    That is, the partition installed in the panel has approximately a lattice shape and includes a discharge space therein, which will be coated with a fluorescent paste. The discharge space is filled with mixing gas of Ne+Xe or He+Ne+Xe for generating ultraviolet rays with a constant pressure. Accordingly, when external electricity is supplied to the discharge space, the fluorescent material emits a visible ray to embody a still or moving image. 
         [0010]    At this point, the partition can be coated with a fluorescent paste by a screen printing method or a dispenser injection method. 
         [0011]    First, in the screen printing method, when a fluorescent paste starts to be discharged, a flexible screen pushes the fluorescent paste to fill the discharge space. Such a screen printing method has been most widely used since the initial development of the PDP. 
         [0012]    As a panel becomes larger-size, the size of the screen should be larger. However, in this case, there is an inconvenience in manufacturing a screen corresponding to the size of the panel. Furthermore, when the screen moves, an imbalance of force occurs. Accordingly, it is difficult to uniformly fill the discharge space of a partition with the fluorescent paste. 
         [0013]    Moreover, as the screen moves in such a way that it surface-contacts with an upper surface of the partition, a tension of a screen mask is increased, thereby reducing a life span thereof. 
         [0014]    Accordingly, recently, instead of the screen printing method, most PDPs have been manufactured by the dispenser injection method. 
         [0015]    The dispenser injection method is a method that fills a discharge space by discharging the fluorescent paste to a discharge space of the partition while moving a dispenser in a previously set direction. 
         [0016]    A pattern and shape position of such a dummy partition is disclosed in U.S. Pat. No. 6,855,026 to Fujinaga et al. issued on Feb. 15, 2005. 
       SUMMARY OF THE INVENTION 
       [0017]    Accordingly, it is an aspect of the present invention to provide a plasma display panel which is capable of effectively reducing noise occurring during operation of the panel by improving the construction of a dummy partition included in a partition. 
         [0018]    It is another object of the present invention to provide a plasma display panel which reduces a rate of defects in a partition due to a uniform coating of a fluorescent paste and continuously moves the dispenser in order to improve productivity. 
         [0019]    The foregoing and/or other aspects of the present invention are achieved by providing a plasma display panel comprising: a front glass including sustain electrodes, each having X and Y electrodes, and dielectric layers for filling the sustain electrodes; a rear glass including address electrodes facing the sustain electrodes of the front glass so as to intersect each other, and dielectric layers for filling the address electrodes; a partition installed between the front glass and the rear glass, and including a main partition and a dummy partition, a plurality of discharge spaces having the same size being formed at the main partition, and a plurality of discharge spaces having different sizes being formed at the dummy partition; and fluorescent layers coated at the respective discharge spaces of the partition. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein: 
           [0021]      FIG. 1  is a schematic view of a procedure in which a fluorescent paste is coated along a moving path of a dispenser; 
           [0022]      FIG. 2  is a partially enlarged view of a pattern of a dummy partition formed at a partition; 
           [0023]      FIG. 3  is an enlarged schematic view of the dummy partition part in the plasma display panel; 
           [0024]      FIG. 4  is a cross-sectional view of a plasma display panel according to the present invention; 
           [0025]      FIG. 5  is a schematic view of a position of a dummy partition formed in a partition among structural elements of the plasma display panel according to the present invention; 
           [0026]      FIG. 6  is an enlarged view of a dummy partition part of the partition according to the present invention; and 
           [0027]      FIG. 7  is a schematic of a state in which the partition of the present invention is coated with a fluorescent material. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Hereinafter, preferable embodiments according to the present invention will be described with reference to the accompanying drawings. In the latter regard, when one element is connected to another element, one element may be not only directly connected to another element but also indirectly connected to another element via a further element. Moreover, irrelevant elements are omitted for clarity. Also, like reference numerals refer to like elements throughout. 
         [0029]      FIG. 1  is a schematic view of a procedure in which a fluorescent paste is coated along a moving path of a dispenser. 
         [0030]    Referring to  FIG. 1 , when a partition  10  is put on a fluorescent paste coating device (not shown), for example, when one dispenser (not shown) is used, a dispenser advances from a side portion of the partition  10  to apply the fluorescent paste. 
         [0031]    After the dispenser advances so as to completely apply the fluorescent paste, the dispenser moves to an adjacent position and then runs in a reverse direction to apply the fluorescent paste. In this respect, moving in the forward and reverse direction is referred to as “one cycle”. 
         [0032]    When fluorescent paste is completely applied during one cycle by moving forward and backward, the dispenser moves to an adjacent position, which is not coated with the fluorescent paste. When the moving of the dispenser is terminated, an interior of the partition can be uniformly coated with the fluorescent paste by repeating the forward and backward movement. 
         [0033]    At this point, a dummy partition  12  is formed at the partition  10  so as to uniformly coat it with the fluorescent paste. The dummy partition  12  is a preliminary region to be coated at the partition  10  so that the fluorescent paste can be initially discharged from the dispenser in a constant amount. 
         [0034]      FIG. 2  is a partially enlarged view of a pattern of a dummy partition formed at a partition. 
         [0035]    Referring to  FIG. 2 , sub partitions  12   a  are formed at both sides of a main partition  13 , and auxiliary partitions  12   b  are formed at both sides of the sub partitions  12   a . The dummy partition  12  is formed so as to include the sub partitions  12   a  and the auxiliary partitions  12   b.    
         [0036]    Thus, when a fluorescent paste is applied to the partition  10  using a dispenser of a paste coating device, the fluorescent paste is first moved and discharged in a transverse direction along a pattern of the auxiliary partition  12   b . When the discharge in the transverse direction is completed, the fluorescent paste is again moved to the sub partition  12   a  and is discharged in a longitudinal direction. Then, the fluorescent paste is coated along a pattern of a main partition  13 . 
         [0037]    However, in a dummy partition  12 , the dispenser passes through the transverse and longitudinal paths to first discharge the fluorescent paste. Accordingly, it takes a long time to coat the main partition with the fluorescent paste. 
         [0038]    Namely, since the dummy partitions  13  are formed at both sides of the main partition  13  so as to have the same shape centered around the main partition  13 . In this respect, the dummy partition  13  is composed of a sub partition  12   a  and an auxiliary partition  12   b . Accordingly, although the main partition  13  is coated with fluorescent materials in the auxiliary partition  12   b  and the sub partition  12   a , the sub partition  12   a  and the auxiliary partition  12   b  should be again coated with the fluorescent paste in the same manner as they were during a first discharge time of the dispenser. 
         [0039]    Furthermore, as the dispenser passes through the transverse and longitudinal paths, a moving path thereof changes. Thus, the time required due to the direction change of the dispenser increases. 
         [0040]    Accordingly, the time required may increase precision, but it will deteriorate the productivity of a display panel. Thus, there is a need for an improved plasma display panel in which both precision and productivity are increased. 
         [0041]      FIG. 3  is an enlarged schematic view of the dummy partition part in the plasma display panel. 
         [0042]      FIG. 3  shows another embodiment of the plasma display panel, and is an enlarged schematic view of a dummy partition part in which only a sub partition is formed, whereas an auxiliary partition is omitted from the dummy partition. 
         [0043]    A discharge space H of a sub partition becomes larger as the dummy partition  12  goes to an end portion of the partition  10 . In particular, because an excitation can occur between the partition  10  and dielectric material during an assembly process of the panel, noise in the discharge space H of an end side increases. 
         [0044]    Namely, in the plasma display panel, since the discharge space H of the end side of the partition  10  among discharge spaces of a sub partition has a box shape, which is not divided, there is no longitudinal partition adhered to the dielectric material so as to break a balance of force. The imbalance of force causes an excitation between the dielectric material and the partition  10 . Accordingly, during operation of the panel, a vibration of the dielectric material and the partition causes a noise to occur. 
         [0045]      FIG. 4  is a cross-sectional view of a plasma display panel according to the present invention;  FIG. 5  is a schematic view of a position of a dummy partition formed in a partition among structural elements of the plasma display panel according to the present invention;  FIG. 6  is an enlarged view of a dummy partition part of the partition according to the present invention; and  FIG. 7  is a schematic view of a state in which the partition of the present invention is coated with a fluorescent material. 
         [0046]    Referring to  FIG. 4 , the plasma display panel  50  according to the present invention includes a front glass  60 , a rear glass  70 , dielectric layers  80 , partitions  90 , and fluorescent layers  95 . The dielectric layers  80  are attached to the front glass  60  and the rear glass  70 , respectively. The partitions  90  are installed between respective dielectric layers  80 , and the fluorescent layers  95  are coated on the respective partitions  90 . 
         [0047]    The front glass  60  and the rear glass  70  are transparent glass, and both surfaces are arranged in parallel with each other so as to face each other at a predetermined interval. 
         [0048]    Sustain electrodes  62  and  64  are installed on the front glass  60 , and are composed of X and Y electrodes. Address electrodes  72  are installed on the rear glass  70  in correspondence to sustain electrodes  62  and  64  on the front glass  60 . 
         [0049]    The address electrodes  72  are arranged between the sustain electrodes  62  and  64 . When an external power source is supplied to the address electrodes  72 , they operate in correspondence with the sustain electrodes  62  and  64 . 
         [0050]    Dielectric layers  80  are formed at the front glass  60  and the rear glass  70 , respectively, in order to fill the sustain electrodes  62  and  64  and the address electrodes  72 . 
         [0051]    A passivation layer  85  is formed on the dielectric layer  80  to protect a surface of the dielectric layer  80 . 
         [0052]    Frits (not shown) are installed at both ends of the front glass  60  and rear glass  70  in order to adhere the front glass  60  and rear glass  70  to each other. 
         [0053]    In this regard, the partitions  90  are formed between the front glass  60  and the rear glass  70 . Discharge spaces for emission of light by the sustain electrodes  62  and  64  and the address electrodes  72  are formed at each of the partitions  90 . 
         [0054]    The partitions  90  can be manufactured so as to have an approximately lattice shape. In this embodiment of the present invention, a lattice type partition is described. However, the present invention is not limited thereto. 
         [0055]    The partitions  90  include main partitions  92  and dummy partitions  96  (see  FIG. 5 ), which allows a screen to be outputted through front and rear panels. The dummy partitions  96  are formed at both ends of the main partition  92 . 
         [0056]    Discharge spaces H are formed at an upper surface of the main partition  92  (see  FIG. 6 ). Fluorescent layers  95  are formed at the discharge space H and emit red (R), green (G), and blue (B) light. 
         [0057]    The dispenser of the fluorescent paste coating device moves in the front and rear directions, and in the left and right directions, so as to inject fluorescent paste in the discharge spaces H, thereby forming fluorescent layers  95  (see  FIG. 4 ). 
         [0058]    In addition to the fluorescent layers  95 , the discharge spaces H are filled with mixing gas of Ne+Xe or He+Ne+Xe to generate ultraviolet rays with a constant pressure. 
         [0059]    The mixing gas is injected and filled in the discharge spaces H during a closed procedure of the front and rear panels  60  and  70 , respectively. 
         [0060]    Furthermore, dummy partitions  96  are formed at both ends of the main partition  92 . Each of the dummy partitions  96  can be divided into a sub partition  96   a  and an auxiliary partition  96   b  (see  FIG. 5 ). 
         [0061]    Discharge spaces H are formed at the sub partition  96   a  (see  FIG. 6 ). The discharge spaces H of the sub partition  96   a  are identical to, greater than or less than the discharge spaces of the main partition  92 . The sub partition  96   a  is formed at an end position of the vertical movement of the dispenser. 
         [0062]    Moreover, the auxiliary partition  96   b  is formed so as to have greater discharge spaces than those of the main partitions  92 . 
         [0063]    That is, the amount of fluorescent paste discharged from the dispenser is more than that of the fluorescent paste which is continuously discharged. In order to make the amount of fluorescent paste initially discharged uniform, the size of the discharge spaces H in the auxiliary partition  96   b  is controlled so as to be greater than that of the discharge spaces H in the main partitions  92 . 
         [0064]    In a detailed description of the auxiliary partition  96   b , the discharge spaces H of the auxiliary partitions  96   b  are divided in the transverse and longitudinal directions.  FIG. 6  shows a schematic of the size and shape of the auxiliary partition. 
         [0065]    As shown in  FIG. 6 , the discharge spaces H of the auxiliary partition  96   b  extend in the transverse and longitudinal directions to form a plurality of discharge spaces H. In consideration of the travel direction and size of a nozzle (not shown) of the dispenser, it is preferred that the longitudinal width of each discharge space H be greater than the transverse width thereof. 
         [0066]    Furthermore, along the travel direction of the dispenser, discharge spaces H of an end side of the auxiliary partition  96   b  gradually become smaller. The reason is that the paste initially discharged from the dispenser passes through large discharge spaces H so that a predetermined amount of the paste can be discharged. 
         [0067]    The following is a procedure for coating a plasma display panel according to the present invention when constructed as described with a fluorescent paste. 
         [0068]    When a moving robot (not shown) moves the partition  90  to a paste coating device, the user operates a controller (not shown) to move the dispenser to a previously set position. 
         [0069]    When movement is completed, the dispenser advances from an auxiliary partition  96   b  of a dummy partition to coat the plasma display panel with the fluorescent paste. 
         [0070]    In this regard, since the fluorescent paste in the dispenser is discharged by air pressure, the initial discharge amount thereof is relatively large. However, when the dispenser passes through the discharge spaces H of the auxiliary partition  96   b , the fluorescent paste is uniformly discharged so as to coat the discharge spaces H of the main partition  92 . 
         [0071]    After all of the discharge spaces H of the main partition  92  are coated with the fluorescent paste, the dispenser is positioned at a formation point of the sub partition  96   a , and the dispenser advances so as to continuously coat the interiors of the discharge spaces H of the sub partition  96   a  with the fluorescent paste. 
         [0072]    When the dispenser advances so as to coat all interiors of the discharge spaces H of the sub partition  96   a  with the fluorescent paste, the dispenser is positioned so as to be completely spaced apart from the sub partition  96   a.    
         [0073]    Accordingly, the interiors of discharge spaces H of the partition  90  may be rapidly and uniformly coated with the fluorescent paste discharged through the dispenser. The discharge spaces H of the auxiliary partition  96   b  extend in the transverse and longitudinal directions. Accordingly, although the panel is adhered due to the maintenance of a balanced force, problems such as excitation do not occur. 
         [0074]    On the other hand, the partition  90  of the present invention is divided into a plurality of blocks. As the dispenser reciprocates (one cycle), the interiors of the discharge spaces H of the main partition  92  may be rapidly coated with fluorescent paste. 
         [0075]    That is, a main partition  92  of the partition  90  is divided into a plurality of blocks. The dispenser advances so as to apply the fluorescent paste, and is returned in an opposite direction to apply fluorescent paste, thereby minimizing movement of the dispenser. This causes a rapid coating to be performed. 
         [0076]    In order to do this, auxiliary partitions  96   b  and sub partitions  96   a  should be alternately formed at both ends of the main partition  92 , in which a plurality of blocks are divided. 
         [0077]    A formation position of the dummy partition  96  can minimize the movement path of the dispenser. 
         [0078]    Referring to  FIG. 7 , in the fluorescent material coating procedure using the dispenser, after the dispenser advances to coat the auxiliary partitions  96   b , the main partitions  92 , and the sub partition  96   a , the dispenser moves to an adjacent position and is returned to its original position. 
         [0079]    As the dispenser is returned to its original position, it passes through the auxiliary partitions  96   b , the main partition  92 , and the sub partitions  96   a . Accordingly, although the dispenser repeats forward and backward movement, a continuous coating of the fluorescent paste can be performed. 
         [0080]    Therefore, the dispenser minimizes the reciprocal movement distance and uniformly coats the partitions and sub partitions with the fluorescent paste. 
         [0081]    As described above, in the plasma display panel according to an embodiment of the present invention, noise occurring during operation of the panel can be effectively reduced by improving the arrangement of the dummy partition included in the partition, thereby enhancing product yield. 
         [0082]    Furthermore, uniform coating of the fluorescent paste can reduce the rate of defects of the partitions to a great extent, and can simplify the movement path of the dispenser, thereby improving productivity and providing satisfaction to manufacturers and users. 
         [0083]    Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.