Abstract:
Disclosed is a display panel module including: a display panel; a film type front filter formed on the display panel for being combined with the display panel; and a ground electrode coupled to an EMI shielding film of the film type front filter and upwardly bent to encompass at least one side of the film type front filter, and thereby preventing the emission of electromagnetic waves to outside.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates in general to a display panel module, more particularly, to a display panel module having a front filter capable of shielding EMI.  
         [0003]     2. Discussion of the Background Art  
         [0004]     In general, PDPs display an image by controlling gas discharge time of each pixel on the basis of digital video data. Typical examples of these PDPs are AC FDPs, as shown in  FIG. 1 . The AC PDP includes three electrodes and is driven by an AC voltage.  
         [0005]      FIG. 1  is a perspective view of a related art AC PDP  30 . More particularly,  FIG. 1  illustrates the structure of a discharge cell corresponding to a sub-pixel.  
         [0006]     As shown in  FIG. 1 , the discharge cell is divided into an upper plate  15  and a lower plate  25 . The upper plate  15  includes an upper substrate  10  where a sustain electrode pair  12 A and  12 B, an upper dielectric layer  14 , and a protective film  16  are formed in sequence. The lower plate  25  includes a lower substrate  18  where a data electrode  20 , a lower dielectric layer  22 , a barrier rib  24 , and fluorescent layers  26  are formed in sequence.  
         [0007]     The upper substrate  10  and the lower substrate  18  are spaced out in parallel by the barrier rib  24 .  
         [0008]     The sustain electrode pair  12 A and  12 B respectively includes a transparent electrode for transmitting visible rays, and a metal electrode for compensating resistance of the transparent electrode. The transparent electrode is relatively wider than the metal electrode.  
         [0009]     The sustain electrode pair  12 A and  12 B includes a scan electrode  12 A and a sustain electrode  12 B. The scan electrode  12 A provides scan signals for determining data supply time and sustain signals for sustaining the gas discharge. On the other hand, the sustain electrode  12 B mainly provides sustain signals for sustaining the discharge.  
         [0010]     The upper dielectric layer  14  and the lower dielectric layer  22  are piled up with charges from the gas discharge.  
         [0011]     The protective film  16  protects the upper dielectric layer  14  from damages caused by a sputtering of plasma and thus, extends lifespan of the PDP and improves the emission efficiency of secondary electrons. The protective film  16  is usually made from magnesium oxide (MgO).  
         [0012]     The dielectric layers  14  and  22  and the protective film  16  lower an externally applied discharge voltage. The data electrode  20  is formed at right angles to the sustain electrode pair  12 A and  12 B. The data electrode  20  provides data signals for selecting cells to be displayed.  
         [0013]     The barrier rib  24  and the upper and lower substrates  10  and  18  create a discharge space. Also, the barrier rib  24  is formed in parallel with the data electrode  20 , and prevents ultraviolet rays generated by the gas discharge from leaking to the adjacent discharge cells.  
         [0014]     The fluorescent layer  26  is applied to the surface of the lower dielectric layer  22  and barrier rib  24 , and generates one of visible rays in red, blue, or blue.  
         [0015]     The discharge space is filled with inert gases including He, Ne, Ax, Xe, and Kr, or different compositions of the inert gas mixtures, or Excimer gas for generating ultraviolet rays by the gas discharge.  
         [0016]     Thusly structured discharge cell is selected by an opposing electrode discharge between the data electrode  20  and the scan electrode  12 A, and is sustained by a surface discharge between the scan electrode  12 A and the sustain electrode  12 B. Therefore, the fluorescent layer  26  is excited by ultraviolet rays generated during the sustain discharge, and visible rays are emitted to the outside of the cell. In this case, the discharge cell controls the cell&#39;s discharge sustain period, namely frequency of the sustain discharge, according to video data, and exits a light at a gray scale level.  
         [0017]      FIG. 2  is a schematic perspective view of a PDP set including the PDP  30  of  FIG. 1 , and  FIG. 3  is a cross-sectional view illustrating one side of the PDP set of  FIG. 2 .  
         [0018]     As shown in  FIG. 2  and  FIG. 3 , the PDP set includes a case  60 , a printed circuit board  50  (hereinafter, it is referred to as “TCB”) housed in the case  60 , a PDP  30 , a glass type front filter  40 , and a cover  70  connected to the case  60  and encompassing the glass type front filter  40 .  
         [0019]     As discussed before with reference to  FIG. 1 , the PDP  30  includes an upper plate  15  and a lower plate  25  being connected to each other.  
         [0020]     The PCB  50  disposed on the rear surface of the PDP  30  includes a plurality of driving and control circuits for driving the sustain electrode pair  12 A and  12 B and the data electrode  20  formed on the PDP  30 . Between the PCB  50  and the PDP  30  is a heat radiation plate  80  for radiating heat emitted from the PDP  30  and the PCB  50 .  
         [0021]     The glass type front filter  40  shields electromagnetic waves generated from the PDP  30  towards the front surface, prevents external light reflection, blocks near-infrared rays, and corrects colors. To this end, the glass type front filter  40  includes, as shown in  FIG. 4 , a first antireflection coating  44  attached to a front surface of a glass substrate  42 , and EMI shielding film  46 , a NIR (near infrared ray) blocking film  48 , a color correcting film  52 , and a second antireflection coating  54 , where the EMI shielding film  46 , the NIR blocking film  48 , the color correcting film  52  and the second and antireflection coating  54  are layered in cited order on the rear surface of the glass substrate  42 .  
         [0022]     The glass substrate  42  is made from a reinforced glass to support the glass type front filter  40  and to protect the front filter  42  and the PDP  30  from damages caused by external impacts. The first and second antireflection coatings  44  and  54  prevent incident light rays from outside from reflecting back to the outside and thus, improve contrast effects.  
         [0023]     The EMI shielding film  46  absorbs electromagnetic waves generated from the PDP  30 , and shields the emission of the electromagnetic waves to outside. The NIR blocking film  48  absorbs near infrared rays at a wavelength band of 800-1000 nm that are generated from the PDP  30 , and blocks the emission of the near infrared rays to outside. This is how infrared rays (approximately 947 nm) generated from a remote controller are normally input to an infrared ray receiver built in the PDP set. The color correcting film  52  contains a color dye to adjust or correct colors, and consequently improves color purity. These films  44 ,  46 ,  48 ,  52 , and  54  are adhered to the glass substrate  42  through an adhesive or glue.  
         [0024]     Referring to  FIG. 5 , the glass tape front filter  40  is electrically connected to the case  60  through a gasket  78  that is coupled to a filter supporter  82 . More specifically, the filter supporter  82  is connected to part of the rear surface of the front filter  40 . At this time, the filter supporter  82  is electrically connected to be EMI shielding film  46  of the glass type front filter  40  spaced apart from the PDP  30 . That is, the filter supporter  82  connects the front filter  40  to the case  60  to shield EMI and/or near infrared rays.  
         [0025]     The case  60  protects the PCB  50 , the glass type front filter  40  and the PDP  30  from external shocks, and shields electromagnetic waves emitted from side and rear surfaces of the PDP  30 . Also, to ensure that the glass type front filter  40  is separated from the PDP  30 , the case  60  is electrically connected to the EMI shielding film  46  of the glass type front filter  40  through the filter supporter  82  that supports the rear surface of the case  60 . Therefore, the case  60  and the EMI shielding film  46  of the glass type front filter are both earthed to a ground voltage and absorb electromagnetic waves emitted from the PDP  30  and discharge them.  
         [0026]     Lastly, the cover  70  encompasses the outside of the glass type front filter  40  and is combined with the case  60 .  
         [0027]     As discussed above, the related art PDP set includes the glass type front filter  40  for shielding electromagnetic waves and correcting optical characteristics. However, because the glass type front filter  40  includes a glass substrate made from the reinforced glass, which is relatively thick, the thickness and weight of the PDP set were increased, and the cost of manufacture was also increased.  
         [0028]     As an attempt to solve the above-described problems, a film type front filter without a glass substrate, as shown in  FIG. 6 , has been suggested. The film type front filter  90  shown in  FIG. 6  includes a color correcting film  98 , a NIR blocking film  96 , and EMI shielding film  94 , and an antireflection coating  92 , each being sequentially adhered to an upper plate  15  of the PDP  30 .  
         [0029]     The antireflection coating  92  prevents incident light rays from outside from reflecting back to the outside. The EMI film  94  absorbs electromagnetic waves generated from the PDP  30  and shields the emission of the electromagnetic waves to outside. The NIR blocking film  96  absorbs near infrared rays that are generated from the PDP  30  and blocks the emission of the near infrared rays to outside. The color correcting film  98  contains a color dye to adjust or correct colors and consequently improves color purity. These films  92 ,  94 ,  96 , and  98  are adhered to the upper plate  15  of the PDP  30  through an adhesive or glue.  
         [0030]     Compared to the glass type front film  40 , the film type front filter  90  is light and made thin. Also, it costs much less to manufacture the film type front filter  90 . However, as the film type front filter  90  is combined with the PDP  30 , the EMI shielding film  94  and the filter supporter located on the rear surface of the film type front filter  90  are not electrically connected to each other. As a result of this, the film type front filter  90  is not capable of shielding the electromagnetic interference.  
       SUMMARY OF THE INVENTION  
       [0031]     An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.  
         [0032]     Accordingly, one object of the present invention is to provide a display panel module with a front filter capable of shielding electromagnetic interference (EMI).  
         [0033]     The foregoing and other objects and advantages are realized by providing a display panel module including a display panel; a film type front filter formed on the display panel for being combined with the display panel; and a ground electrode coupled to an EMI shielding film of the film type front filter and upwardly bent to encompass as least one side of the film type front filter and thereby preventing the emission of electromagnetic waves to outside.  
         [0034]     Another aspect of the present invention provides a display panel module including: a display panel; a film type front filter formed on the display panel; and a conductive tape for electrically earthing the film type front filter.  
         [0035]     The display panel module of the present invention uses the conductive tape for earthing the EMI shielding film by adhering the conductive tape from inside to outside the front filter. Therefore, the electromagnetic waves and/or near infrared rays of the PDP with the film type front filter can be more effectively shielded.  
         [0036]     Moreover, since the black material included in the EMT shielding film is formed on the side where the user can see, contrast deterioration (tonal fading) can be prevented. Also, since the conductive metal patterning and the black material patterning are carried out at the same time, the black layer forming process can be eliminated and as a result of this, the manufacture process is much simplified and the cost of manufacture is reduced.  
         [0037]     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0038]     The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:  
         [0039]      FIG. 1  is a perspective view of a related art three-electrode AC surface discharge plasma display panel (PDP);  
         [0040]      FIG. 2  is an exploded perspective view of a PDP set including a PDP of  FIG. 1 ;  
         [0041]      FIG. 3  is a cross-sectional view showing the vertical structure of a DPD set of  FIG. 2 ;  
         [0042]      FIG. 4  is a cross-sectional view showing the vertical structure of a glass type front filter and PDP of  FIG. 2 ;  
         [0043]      FIG. 5  is a cross-sectional view showing in detail the connection relation between a glass type front filter and a filter supporter;  
         [0044]      FIG. 6  is a cross-sectional view showing the vertical structure of a PDP to which a related art film type front filter is attached;  
         [0045]      FIG. 7  is a cross-sectional view showing the vertical structure of a PDP to which a film type front filter of the present invention is attached; and  
         [0046]      FIG. 8  is a cross-sectional view showing in detail the connection relation between a film type front filter of  FIG. 7  and a filter supporter. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0047]     The following detailed description will present a preferred embodiment of the invention in reference to the accompanying drawings  FIGS. 7 and 8 .  FIG. 7  is a cross-sectional view a film type front filter of the present invention.  
         [0048]     As shown in  FIG. 7 , the film type front filter  160  includes an EMI shielding film  172  and an antireflection coating  162 , which are formed sequentially on an upper plate  115  of a PDP  130 .  
         [0049]     The antireflection coating  162  is formed on the front surface of a first base film  120  and prevents incident light rays from outside from reflecting back to the outside.  
         [0050]     The EMI shielding film  172  absorbs electromagnetic waves generated from the PDP  130  and shields the emission of the electromagnetic waves to outside. The EMI shielding film  172  is formed on the rear surface of the first base film  120  and its front surface is adhered to the rear surface of a second base film  122  through an adhesive  126 . The EMI shielding film  172  includes a conducive mesh  168 , and a black frame  170  for supporting the conductive mesh  168 .  
         [0051]     The conductive mesh  168  is formed on an effective screen area, and to obtain high visible light transmittance from the PDP  130  it creates polygon shaped holes therebetween.  
         [0052]     The conductive mesh  168  is formed by patterning black material  164   a  and a metal layer  164   b  formed on the black material  164   a  through a photolithography process.  
         [0053]     The metal layer  164   b  is either a double metal layer composed of a first metal layer made from silver (Ag) or copper (Cu) and a second metal layer made from a transparent conductive material, or a single metal layer composed of the first metal layer only.  
         [0054]     If the metal layer is composed of the first and second metal layers, the EMI shielding film  172  alone can absorb near infrared rays generated from the PDP  130  and shield the emission of the near infrared rays to outside. On the other hand, if the EMI shielding film  172  includes the single metal layer, the film type front filter  160  needs a separate NIR blocking film (not shown).  
         [0055]     The black frame  170  is foxed outside the effective screen area, that is, on non-effective screen area. The black frame  170  is made from the same material with the conductive mesh  168 .  
         [0056]     Here, the black material  164   a  included in the black frame  170  and the conductive mesh  168  is made from at least one pigment or dye selected from a group consisting of titanium oxide (rutile structure, anatase structure), cadmium yellow, lead-tin yellow, molybdate orange, cadmium red, iron oxide, copper phtalocyanine green/blue/ultramarine blue, carbon black, torchsky, phtalocyanine green, cobalt blue, cobalt bio red, mineral bio red, chromium oxide, indanthrene blue, carbon I, carbon II, phtalocyanine blue, aniline black, azo pigment, azo dye, azo compounds, azo basic oxide pigment, metal complex salts, metals, and metal oxides. Also, the black material  164   a  is made from an aniline-formaldehyde resin, a material from the aryl group, or an arylation product resin. Also, the black material  164   a  is made from an inorganic material containing metal like Nd 2 O 3 , Nd group, Fe and iron oxides, Ag and silver oxides, Ni and nickel oxides, and Cr and chromium oxides.  
         [0057]     Alternatively, the EMI shielding film  172  can be a single layer as well, which is formed by patterning the metal layer made of Ag, Cu, Au or Al, and blackening the surface of the metal pattern. This type of EMI shielding film  172  formed of the black metal layer not only shields the emission of the electromagnetic waves from the PDP  130  to outside, but also is used as a black frame for defining the effective screen area.  
         [0058]     A color correcting film (not shown) contains a dye for color adjustment, so that the colors can be adjusted to increase color purity.  
         [0059]     These films (the EMI shielding film  172  and the antireflection coating  162 ) are formed, more specifically, adhered on the base films  120 ,  122 , and  124  through an adhesive or glue, and are attached to the upper plate  115  of the PDP  130 .  
         [0060]     The upper and lower plates  115 ,  125  of the PDP  130  are cohered to each other, creating a gas discharge space therebetween. Using this gas discharge, the PDP displays an image.  
         [0061]     A conductive tape  176  of the film type front filter of the invention has a “C” shape or “c” shape so that the conductive tape  176  is connected to the EMI shielding film  172  and at the same time encompasses the side of the film type front filter  160 . As shown in  FIG. 8 , the conductive tape  176  is electrically connected to a covet  180  or a case (not shown) trough a spring gasket  178  coupled to the filter supporter  182 , and is used as a ground electrode for earthing the black frame  170  of the EMI shielding film with the case. In other words, the EMI shielding film  172  is electrically connected to the case through the conductive tape  176 , and serves to shield electromagnetic waves and/or near infrared rays. As for the conductive tape  176 , a silver (Ag) fiber tape, a silver (Ag) paste, a nickel (Ni) fiber tape, a copper (Cu) tape, or a metal alloy, each having a thickness of 10-300 μm, is used  
         [0062]     Referring to  FIG. 8 , the conductive tape  176  is first taped on the black frame  170  of the EMI shielding film  172 . Then the conductive tape  176  is bent in such a manner to encompass at least one side of the film type front filter  160  and is taped to the edge of the antireflection coating  162 .  
         [0063]     After taping the conductive tape  176  on the black frame  170  of the EMI shielding film  172 , an adhesive  126  is applied to the rear surface of the conductive tape  176  or on the upper plate  115  of the PDP  130  so that the conductive tape  176  is well adhered to the side of the front filter  160  and the edge of the antireflection coating  162  on the top of the front filter  160 . The adhesive applied to the rear surface of the conductive tape  176  or the upper plate  115  of the PDP  130  is used to combine the PDP  130  with the film type front filter  160 .  
         [0064]     Alternatively, at least part of the conductive tape  176  can be a double sided tape. In this manner, the conductive tape  176  is taped to the black frame  170  of the EMI shielding film and to the upper plate  115  of the PDP  130  as well.  
         [0065]     Afterwards, the conductive tape  176  is upwardly bent to encompass the side of the film type front filter  160  and then is taped to the edge of the antireflection coating  162 . Therefore, the conductive tape  176  can earth the black frame  170  with the case and through this conductive tape  176  the PDP  130  and the film type front filter  160  are combined together.  
         [0066]     As described above, the conductive tape  176  is taped to the upper plate  115  of the PDP  130  through glue or an adhesive  126 . Alternatively, the conductive tape  176  can be made relatively thin. In such case, a separate adhesive or glue is used to adhere the conductive tape  176  to the upper plate  115  of the PDP  130 .  
         [0067]     In conclusion, the display panel module of the present invention uses the conductive tape for earthing the EMI shielding film by adhering the conductive tape from inside to outside the front filter. Therefore, the electromagnetic waves and/or near infrared rays of the PDP with the film type front filter can be more effectively shielded.  
         [0068]     Moreover, since the black material included in the EMI shielding film is formed on the side where the user can see, contrast deterioration (tonal fading) can be prevented. In addition, since the conductive metal patterning and the black material patterning are carried out at the same time, the black layer forming process can be eliminated and this consequently simplifies the manufacture process and reduces the cost of manufacture.  
         [0069]     While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.  
         [0070]     The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.