Patent Publication Number: US-2009220798-A1

Title: Display panel

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2008-0019619, filed on Mar. 3, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a display panel, and more particularly, to a filter assembly of a display panel. 
     2. Description of the Related Art 
     Generally, flat display panels can be classified into light emitting flat display panels and light receiving flat display panels. Light emitting flat display panels include flat cathode ray tubes, plasma display panels, field emission display panels, and light emitting diode display panels. Light receiving flat display panels include liquid crystal display panels. 
     A plasma display panel is a flat panel display device that displays desired numbers, letters, or graphics using visible light emitted from phosphor layers excited by ultraviolet rays generated during a gas discharge that is initiated by applying a discharge voltage to a plurality of discharge electrodes formed on a plurality of substrates. A discharge gas is sealed between the plurality of substrates. 
     Referring to  FIG. 1  that is a cross-sectional view of a conventional plasma display panel  100 , the conventional plasma display panel  100  includes a panel assembly  101 , a filter assembly  103  that is coupled to the front of the panel assembly  101  via a supporting member  102 , a driving circuit unit  104  that is installed on the rear side of the panel assembly  101  and includes a circuit element  105 , and a case  106  that contains the panel assembly  101 , the filter assembly  103 , and the driving circuit unit  104 . The filter assembly  103  is coupled (e.g., grounded) to a chassis inside the case  106  via a conductive line  107 . 
     The conventional plasma display panel  100  discharges electromagnetic wave, infrared ray, or neon luminescence at a wavelength of about 590 to 600 nanometers from the panel assembly  101  or the circuit element  105  of the driving circuit unit  104 . 
     The filter assembly  103  blocks most emission in a neon luminescent region at a wavelength of about 590 to 600 nanometers. However, since a new phosphor layer having a new luminescent spectrum has been developed, a wavelength having a reduced color purity in a neon luminescent region and other regions is generated as well. 
     Nevertheless, a phosphor layer having a luminescent spectrum in an unnecessary region can enhance saturation of brightness, an afterimage, etc. in addition to a color purity, and thus it can be obliged to use the conventional plasma display panel in spite of some disadvantages. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention provide a display panel having an enhanced structure in which a filter assembly can improve color purity. 
     According to an embodiment of the present invention, there is provided a display panel including: a panel assembly having a plurality of substrates for displaying an image by utilizing luminescence of a phosphor layer in the panel assembly; and a filter assembly coupled to the panel assembly and having a minimum transmittance at a wavelength between 550 and 580 nanometers. 
     The filter assembly may include: a base film; an adhesive layer on the base film; and an absorption coloring material included in the adhesive layer, wherein the absorption coloring material may include a compound having a maximum absorption rate at the wavelength between 550 and 580 nanometers. 
     A filter assembly may include: a base film; and an absorption coloring layer coated on a side of the base film and including a compound having a maximum absorption rate at the wavelength between 550 and 580 nanometers. 
     The absorption coloring material may include a cyanine derivative dye and an acryl derivative binder. 
     The absorption coloring material may include a squarylium derivative dye and an acryl derivative binder. 
     The filter assembly may be adhered to a front surface of the panel assembly. 
     The filter assembly may include: a base glass; an adhesive layer on a side of the base glass; and an absorption coloring material included in the adhesive layer, wherein the absorption coloring material may include a compound having a maximum absorption rate at the wavelength between 550 and 580 nanometers. 
     The filter assembly may include: a base glass; and an absorption coloring layer on the base glass, wherein the absorption coloring layer may include a compound having a maximum absorption rate at the wavelength between 550 and 580 nanometers. 
     The filter assembly may be spaced apart from the panel assembly by a gap. 
     The minimum transmittance of the filter assembly may include a first minimum transmittance at a wavelength between 490 and 500 nanometers and a second minimum transmittance at a wavelength between 590 and 600 nanometers. 
     The minimum transmittance of the filter assembly may include a transmittance between 0.01 and 40% at the wavelength between 490 and 500 nanometers and at the wavelength between 590 and 600 nanometers. 
     The filter assembly may have a visible light transmittance between 20 and 90%. The phosphor layer may include a red phosphor layer formed of Y(P,V)O4;Eu, a green phosphor layer formed of YAl3(BO3)Tb, and a blue phosphor layer formed of BaMgAl10O17:Eu. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features and aspects of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
         FIG. 1  is a cross-sectional view of a conventional plasma display panel; 
         FIG. 2  is an exploded perspective view of a plasma display panel according to an embodiment of the present invention; 
         FIG. 3  is a partial cross-sectional view of the plasma display panel shown in  FIG. 2  according to an embodiment of the present invention; 
         FIG. 4  is a partial cross-sectional view of a filter assembly according to an embodiment of the present invention; 
         FIG. 5  is a graph illustrating a spectrum of a phosphor layer according to an embodiment of the present invention; 
         FIG. 6  is a graph illustrating a spectrum of a filter assembly according to an embodiment of the present invention; 
         FIG. 7  is a graph illustrating a spectrum of a filter assembly according to another embodiment of the present invention; 
         FIG. 8  is a partial cross-sectional view of a filter assembly according to another embodiment of the present invention; 
         FIG. 9  is a partial cross-sectional view of a filter assembly according to another embodiment of the present invention; 
         FIG. 10  is a partial cross-sectional view of a filter assembly according to another embodiment of the present invention; 
         FIG. 11  is a partial cross-sectional view of a filter assembly according to another embodiment of the present invention; 
         FIG. 12  is a partial cross-sectional view of a filter assembly according to another embodiment of the present invention; 
         FIG. 13  is an enlarged partial cross-sectional view of a modification of the filter assembly shown in  FIG. 4  according to an embodiment of the present invention; 
         FIG. 14  is an enlarged partial cross-sectional view of a modification of the filter assembly shown in  FIG. 8  according to an embodiment of the present invention; 
         FIG. 15  is an enlarged partial cross-sectional view of a modification of the filter assembly shown in  FIG. 8  according to another embodiment of the present invention; 
         FIG. 16  is an enlarged partial cross-sectional view of a modification of the filter assembly shown in  FIG. 11  according to an embodiment of the present invention; 
         FIG. 17  is an enlarged partial cross-sectional view of a modification of the filter assembly shown in  FIG. 11  according to another embodiment of the present invention; and 
         FIG. 18  is an enlarged partial cross-sectional view of a modification of the filter assembly shown in  FIG. 11  according to another embodiment of the present invention. 
         FIG. 19  is a perspective view of a rear panel of a plasma display panel according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Hereinafter, exemplary embodiments of the present invention will be described more fully with reference to the accompanying drawings, in which the exemplary embodiments of the invention are shown. 
       FIG. 2  is an exploded perspective view of a plasma display panel  200  according to an embodiment of the present invention. 
     Referring to  FIG. 2 , the plasma display panel  200  includes a panel assembly  210 , a filter assembly  220  adhered to the front of the panel assembly  210 , a chassis base assembly  230  connected to the rear side of the panel assembly  210 , a driving circuit unit  240  (shown in  FIG. 3 ) installed on the rear side of the chassis base assembly  230 , and a case  250  for storing the panel assembly  210 , the filter assembly  220 , the chassis base assembly  230 , and the driving circuit unit  240 . 
       FIG. 19  is a perspective view of a rear panel of a plasma display panel according to an embodiment of the present invention. Referring to  FIG. 19 , The rear panel  320  includes a rear substrate  321 , address electrodes  322  formed on a front surface  321  a of the rear substrate  321  crossing the sustain electrode pairs, a rear dielectric layer  323  covering the address electrodes  322 , barrier ribs  324  formed on the rear dielectric layer  323  to partition discharge cells  326 , and a phosphor layer  325  disposed in each discharge cell. 
       FIG. 3  is a partial cross-sectional view of the plasma display panel  200  shown in  FIG. 2  according to an embodiment of the present invention. 
     Referring to  FIG. 3 , the panel assembly  210  includes a first substrate  211  and a second substrate  212  facing and connected to the first substrate  211 . An inner space between the first substrate  211  and the second substrate  212  is sealed from the outside by coating a sealing member such as frit glass along inner edges of the front substrate  211  and the second substrate  212  that face each other. 
     If the panel assembly  210  is a surface discharge type panel, a discharge electrode is buried in a dielectric layer between the first substrate  211  and the second substrate  212 . Discharge cells are defined by barrier ribs. Red, green, and blue phosphor layers are coated in the discharge cells. A discharge gas such as a Ne—Xe gas or a He—Xe gas is filled in the discharge cells. 
     The filter assembly  220  is adhered to the front side of the first substrate  211  through which visible light transmits. The filter assembly  220  is formed by stacking a plurality of functional films in order to block electromagnetic waves, ultraviolet rays, neon luminescent light or the reflection of external light that is generated from the panel assembly  210 . 
     A chassis base  231  included in the chassis base assembly  230  is connected to the rear side of the second substrate  212  via an adhesion member  260 . The adhesion member  260  is adhered to the rear center of the second substrate  212  and includes a thermal conductive sheet  261  that serves as thermal conductive medium for transferring heat generated from the panel assembly  210  while driven to the chassis base  231  and a double-sided tape  262  that fixes (or secure) the chassis base  231  to the panel assembly  210 . 
     The driving circuit unit  240  is installed on the rear side of the chassis base  231  opposite to a side of the chassis base  231  where the panel assembly  210  is installed. A plurality of circuit elements  241  are embedded in the driving circuit unit  240 . An end of a signal transferring unit  232  such as, but not limited to, a flexible printed cable is connected to the driving circuit unit  240  in which the plurality of circuit elements  241  are included. Another end of the signal transferring unit  232  is connected to terminals of each pair of discharge electrodes of the panel assembly  210  and inter-transfers electrical signals between the panel assembly  210  and the plurality of circuit elements  241 . 
     The signal transferring unit  232  includes a driving integrated circuit (IC)  233 , a plurality of leads  234  electrically connected to the driving IC  233 , and a flexible film  235  for enclosing the plurality of leads  234 . 
     A chassis reinforcing member  236  is adhered to the top and bottom ends and the rear side of the chassis base  231  in order to reinforce the rigidity of the chassis base  231 . A cover plate  237  is installed on the rear end of the chassis base  231  in order to prevent the signal transferring unit  232  from damage. 
     The signal transferring unit  232  is disposed between the rear end of the chassis base  231  and the cover plate  237 . Thermal grease  271  is disposed between the driving IC  233  and the chassis reinforcing member  236 . A silicon sheet  272  is disposed between the driving IC  233  and the cover plate  237 . 
     The case  250  (shown in  FIG. 1 ) includes a front cabinet  251  installed in the front of the filter assembly  220  and a back cover  252  installed in the rear of the driving circuit unit  240 . A plurality of through-holes  253  are formed in the top and bottom ends of the back cover  252 . 
     The filter assembly  220  includes a film having a minimum transmittance at a wavelength between  550  and  580  nanometers. 
     The filter assembly  220  will be described in more detail below. 
     Like reference numerals in the previous figures denote like elements in the figures described below. [ 0059 ]  FIG. 4  is a partial cross-sectional view of a filter assembly  400  according to an embodiment of the present invention. Referring to  FIG. 4 , the filter assembly  400  includes a first base film  401 . The first base film  401  is formed of, for example, a high polymer resin selected from the group consisting of Polyethersulfone (PES), Polyacrylate (PAC), Polyetherimide (PEI), Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), Polyphenylene Sulfide (PPS), Polyimide (PI), Polycarbonate (PC), Cellulous Triacetate (CT), Cellulose Acetate Propionate (CAP), and combinations thereof. 
     A first adhesive layer  402  is disposed between a surface of the first base film  401  and the first substrate  211 . The first adhesive layer  402  can be formed of, but is not necessarily restricted thereto, a polymer adhesive such as a PSA adhesive layer and a rubber adhesive material. The filter assembly  400  is adhered to the front side of the first substrate  211  via the first adhesive layer  402 . 
     An electromagnetic wave shield filter  403  is adhered to another surface of the first base film  401 . The electromagnetic wave shield filter  403  is used to shield electromagnetic wave generated when the plasma display panel  200  is operating. The electromagnetic wave shield filter  403  is patterned in the form of a fine metal mesh. The electromagnetic wave shield filter  403  may be formed of an electrical conductive material such as copper, silver, aluminum, platinum, steel, and an alloy thereof. Alternatively, the electromagnetic wave shield filter  403  may be formed of a conductive ceramic material or a conductive carbon nanotube. 
     The electromagnetic wave shield filter  403  can be manufactured using various methods in order to pattern it in a metal mesh shape. For example, a plating or etching method is simpler in view of manufacturing processing and is suitable to patterning. 
     The electromagnetic wave shield filter  403  can be stacked by oxidizing a transparent conductive film such as an ITO film and a conductive metal layer such as copper formed thereon according to various embodiments of the present invention. 
     A ground line  280  shown in  FIG. 3  is connected to the electromagnetic wave shield filter  403  through an area and is connected (or grounded) to the chassis base  231  or a conductive member of a front cabinet  251  shown in  FIG. 3 . 
     A second adhesive layer  404  is formed on the electromagnetic wave shield filter  403  in order to cover the electromagnetic wave shield filter  403 . The second adhesive layer  404  may be formed of a polymer adhesive such as a PSA adhesive layer and a rubber adhesive material, like the first adhesive layer  402 . 
     An absorption coloring material  405  is mixed in the second adhesive layer  404 . The absorption coloring material  405  may include a compound having a maximum absorption ratio at a wavelength between  550  and  580  nanometers. 
     The reason for forming the absorption coloring material  405  is as follows. 
     The panel assembly  210  includes a phosphor layer that emits visible light by absorbing ultraviolet rays generated by a discharge gas such as an Xe gas filled in the discharge cells that is excited by a discharge voltage applied to discharge electrodes when the panel  200  is discharged. 
     For example, the phosphor layer may be a photo luminescence phosphor (PL) layer that emits light by a photo luminescence mechanism. For example, the phosphor layer is formed of a material having luminescence efficiency at 147 nanometers so that it can be excited by vacuum ultraviolet rays generated from the Xe gas at 147 nanometers. 
     The phosphor layer may include one of a red phosphor layer, a green phosphor layer, or a blue phosphor layer in each discharge cell so that the panel  200  forms a color image. As such, each phosphor layer forms a sub-pixel. 
     The red phosphor layer may be formed of Y(P,V)O 4 ;Eu, the green phosphor layer may be formed of YAl 3 (BO 3 )Tb, and the blue phosphor layer may be formed of BaMgAl 10 O 17 :Eu. Alternatively, the blue phosphor layer may be formed of CaMgSi 2 O 6 :Eu or a compound of BaMgAl 10 O 17 :Eu and CaMgSi 2 O 6 :Eu, but the present invention is not limited thereto. 
     After the excited discharge gas in discharge spaces of the panel  200  is discharged, some electrons generated according to an ionization reaction do not collide to release energy and remain in the discharge spaces, therefore, the phosphor layer may include an additional phosphor layer that changes kinetic energy of the electrons to visible light in the discharge spaces in order to avoid loss of energy of the electrons, thereby preventing the energy from transforming to heat and preventing temperature increase. 
     The additional phosphor layer may be a cathode luminescence phosphor (CL) layer or a quantum dot phosphor (QD) layer. The CL layer may be formed of sulfide phosphor. The QD layer emits light when atoms are stabilized at an atom energy level by receiving external energy since atoms do not interfere with each other. Thus, discharge gas can be excited at a low voltage, thereby increasing efficiency and enabling printing processing that is suitable to a large-sized panel. 
     In the phosphor layer that includes the red phosphor layer formed of Y(P,V)O 4 ;Eu, the green phosphor layer formed of YAl 3 (BO 3 )Tb, and the blue phosphor layer formed of BaMgAl 10 O 17 :Eu, green color purity is reduced in a green region corresponding to, for example, a wavelength between 550 and 580 nanometers, in some embodiments of the present invention, between 550 and 560 nanometers, and color re-expression is lowered. 
     To avoid or reduce such problem, the second adhesive layer  404  includes the absorption color material  405 . The absorption color material  405  includes a compound having a maximum absorption ratio at a wavelength, for example, between 550 and 580 nanometers. 
     The absorption coloring material  405  may be formed of a compound of a cyanine derivative dye and an acryl derivative binder or a compound of a squarylium derivative dye and the acryl derivative binder. 
     The filter assembly  400  including the absorption coloring material  405  has a minimum transmittance at a wavelength between 550 and 580 nanometers that includes a luminescent spectrum of a green region. 
     The absorption coloring material  405  has a maximum absorption rate at each wavelength of a blue region corresponding to a wavelength between 490 and 500 nanometers and a neon region corresponding to a wavelength between 590 and 600 nanometers in order to absorb each wavelength in the luminescent spectrum. 
     One surface of a second base film  406  is adhered to the surface of the second adhesive layer  404  in which the absorption coloring material  405  is mixed. The second base film  406 , like the first base film  401 , is formed of, for example, a high polymer resin selected from the group consisting of Polyethersulfone (PES), Polyacrylate (PAC), Polyetherimide (PEI), Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), Polyphenylene Sulfide (PPS), Polyimide (PI), Polycarbonate (PC), Cellulous Triacetate (CT), Cellulose Acetate Propionate (CAP), and combinations thereof. 
     A reflection preventive layer  407  is formed on another surface of the second base film  406 . 
     The reflection preventive layer  407  includes an anti-reflection (AR) film layer  408  and an anti-glare (AG) film layer  409  in order to prevent a drop of visibility due to the reflection of an external light. However, the reflection preventive layer  407  may include one of the AR film layer  408  and the AG film layer  409  or may further include a hard coating layer, but the present invention is not limited thereto. 
     The thickness of the reflection preventive layer  407  may be between 2 and 7 micrometers. The hardness of a lead pencil is between 2 and 3 H. A haze value may be between 1 and 7%. When the reflection preventive layer  407  includes the AR film layer  408 , a difference of a light phase between a low refraction layer and a high refraction layer results in an offset of light and a reduction thereof. When the reflection preventive layer  407  includes the AG film layer  409 , a protrusion having a diameter between 1 nanometer and 1 millimeters, in some embodiments, between 0.5 and 20 micrometers is formed on the surface of the AG film layer  409  to scatter light. 
     A third base film  410  is formed on the surface of the reflection preventive layer  407  in order to prevent damage of the filter assembly  400 . 
     In some embodiments, referring to  FIG. 13 , the absorption coloring material  405  is mixed in the first adhesive layer  402  or both the first adhesive layer  402  and the second adhesive layer  404 , but the present invention is not limited thereto. 
     The filter assembly  400  may further include a near infrared shield layer or a transmission adjustment layer. The near infrared shield layer is used to shield unnecessary luminescence of near infrared rays generated by plasma of an inert gas that is used for emission to display an image. The transmission adjustment layer is used to adjust an amount of transmitted light. In addition, the filter assembly  400  may include the above functions to an adhesive layer (e.g., adhesive layers  402  and  404 ) or further form a film having various functions. 
     The filter assembly  400  maintains a light transmittance between  20  and  90  % with regard to visible light that transmits through the first substrate  211  by exciting the phosphor layer according to ultraviolet rays generated by a discharge of the panel assembly  210 . A haze value of the filter assembly  400  may be between 1 and 15% in view of characteristics of a light. If the haze value exceeds 15%, a display device emits a hazy light. 
       FIG. 5  is a graph illustrating a spectrum of a phosphor layer according to an embodiment of the present invention. 
     The phosphor layer includes the red phosphor layer formed of Y(P,V)O 4 ;Eu, the green phosphor layer formed of YAl 3 (BO 3 )Tb, and the blue phosphor layer formed of BaMgAl 10 O 17 :Eu. 
     Referring to  FIG. 5 , the spectrum of the phosphor layer reaches a peak in a region A of a green wavelength between 550 and 560 nanometers and has a high transmittance greater than 80%. The transmittance reduces a color purity of the region A at the green wavelength and lowers a color re-expression. 
       FIG. 6  is a graph illustrating a spectrum of the filter assembly  400  including the absorption coloring material  405  according to an embodiment of the present invention. 
     Referring to  FIG. 6 , the filter assembly  400  has a transmittance between 0.01 and 40% in a region B of a green wavelength between 550 and 580 nanometers. Thus, a color coordination moves from green or yellow color to green color in the region B of the green wavelength, thereby increasing a color re-expression of the filter assembly  400 . 
       FIG. 7  is a graph illustrating a spectrum of the filter assembly  400  according to another embodiment of the present invention. Referring to  FIG. 7 , the filter assembly  400  has a transmittance between 0.01 and 40% in a region C of a green wavelength between 550 and 580 nanometers, a transmittance between 0.01 and 40% in a region D of a blue wavelength between 490 and 500 nanometers. Also, the filter assembly  400  has a transmittance between 0.01 and 40% in a region E of a neon wavelength between 590 and 600 nanometers, thereby increasing a color re-expression of the filter assembly  400 . 
       FIG. 8  is a partial cross-sectional view of a filter assembly  800  according to another embodiment of the present invention. 
     Referring to  FIG. 8 , the filter assembly  800  includes a first base film  801  and a second base film  806 . The first and second base films  801  and  806  are formed of the same material, for example, a high polymer resin selected from the group consisting of Polyethersulfone (PES), Polyacrylate (PAC), Polyetherimide (PEI), Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), Polyphenylene Sulfide (PPS), Polyimide (PI), Polycarbonate (PC), Cellulous Triacetate (CT), Cellulose Acetate Propionate (CAP), and combinations thereof. 
     A first adhesive layer  802  that is formed of, for example, a polymer adhesive and a rubber adhesive material is disposed between a surface of the first base film  801  and the first substrate  211 , so that the filter assembly  800  is adhered to the first substrate  211 . 
     An electromagnetic wave shield filter  803  is adhered to another surface of the first base film  801 . The electromagnetic wave shield filter  803  may be formed by patterning a fine metal mesh or oxidizing and stacking conductive metal layers. 
     A second adhesive layer  804  that is formed of, for example, a polymer adhesive and a rubber adhesive material is coated on the electromagnetic wave shield filter  803 . In the present embodiment, an absorption coloring material is not mixed in the second adhesive layer  804 , but an absorption coloring layer  805  is formed on the surface of the second adhesive layer  804 . The absorption coloring layer  805  may include a compound having a maximum absorption rate at a wavelength between 550 and 580 nanometers. The absorption coloring layer  805  may be formed of a compound of a cyanine derivative dye and an acryl derivative binder or a compound of a squarylium derivative dye and the acryl derivative binder. 
     The absorption coloring layer  805  has a maximum absorption rate at each wavelength of a blue region corresponding to a wavelength between 490 and 500 nanometers and a neon region corresponding to a wavelength between 590 and 600 nanometers in order to absorb each luminescent spectrum. 
     One surface of the second base film  806  is adhered to the surface of the second absorption coloring layer  805 . A reflection preventive layer  807  is formed on another surface of the second base film  806 . The reflection preventive layer  807  may be formed by stacking an AR film layer  808  and an AG film layer  809  or may include any one of layers  808  and  809 . A third base film  810  is adhered to the surface of the reflection preventive layer  807 . 
     The absorption coloring layer  805  may be disposed between the second base film  806  and the reflection preventive layer  807  as shown in  FIG. 14  or, may be disposed between the first base film  801  and the first adhesive layer  802  as shown in  FIG. 15 , but the present invention is not limited thereto. 
       FIG. 9  is a partial cross-sectional view of a filter assembly  900  according to another embodiment of the present invention. 
     Referring to  FIG. 9 , the filter assembly  900  includes a base glass  901 . The base glass  901  is a thick film type glass unlike a thin film base film shown in  FIGS. 4 and 8 . 
     An electromagnetic wave shield filter  903  is adhered to one surface of the base glass  901 , i.e., the surface of the base glass  901  facing the first substrate  211 . The electromagnetic wave shield filter  903  is formed, for example, by patterning a fine metal mesh or oxidizing and stacking a transparent conductive film such as an ITO film and a conductive metal layer such as copper layers on the transparent conductive film, but the present invention is not limited thereto. 
     The electromagnetic wave shield filter  903  is spaced apart from the first substrate  211  so that a gap g is formed between the filter assembly  900  and the first substrate  211 . 
     An adhesive layer  904  is coated on another surface of the base glass  901 . The adhesive layer  904  is formed of, for example, a polymer adhesive such as a PSA adhesive layer or a rubber adhesive material, but the present invention is not limited thereto. 
     An absorption coloring material  905  is mixed in the adhesive layer  904 . The absorption coloring material  905  may include a compound having a maximum absorption ratio at a wavelength between 550 and 580 nanometers. The absorption coloring material  905  may be formed of a compound of a cyanine derivative dye and an acryl derivative binder or a compound of a squarylium derivative dye and the acryl derivative binder. 
     The filter assembly  900  including the absorption coloring material  905  has a minimum transmittance at a wavelength between 550 and 580 nanometers that includes a luminescent spectrum of a green region. 
     The absorption coloring material  905  has a maximum absorption rate at a wavelength of a blue region corresponding to a wavelength between 490 and 500 nanometers, at a wavelength of a neon region corresponding to a wavelength between 590 and 600 nanometers, or at the wavelengths of the blue region corresponding to the wavelength between 490 and 500 nanometers and the neon region corresponding to the wavelength between 590 and 600 nanometers. 
     One surface of a second base film  906  is adhered to the surface of the adhesive layer  904  in which the absorption coloring material  905  is mixed. The second base film  906  is formed of, for example, a high polymer resin selected from the group consisting of Polyethersulfone (PES), Polyacrylate (PAC), Polyetherimide (PEI), Polyethylene Naphthalate (PEN), Polyethylene Terephthalate (PET), Polyphenylene Sulfide (PPS), Polyimide (PI), Polycarbonate (PC), Cellulous Triacetate (CT), Cellulose Acetate Propionate (CAP), and combinations thereof. 
     A reflection preventive layer  907  is formed on another surface of the first base film  906 . The reflection preventive layer  907  is formed, for example, by stacking an AR film layer  908  and an AG film layer  909  together or any one of them. A second base film  910  is formed on the surface of the reflection preventive layer  907 . 
     The filter assembly  900  may further include a near infrared shield layer or a transmission adjustment layer. In addition, the filter assembly  900  may include a filter function in an adhesive layer or further form a film having various functions. 
       FIG. 10  is a partial cross-sectional view of a filter assembly  1000  according to another embodiment of the present invention. 
     Referring to  FIG. 10 , the filter assembly  1000  includes a base glass  1001 . An electromagnetic wave shield filter  1002  is adhered to one surface of the base glass  1001 , i.e., the surface of the base glass  1001  facing the first substrate  211 . The electromagnetic wave shield filter  1002  is spaced apart from the first substrate  211  so that a gap g is formed between the filter assembly  1000  and the first substrate  211 . 
     A first adhesive layer  1004  is formed on another surface of the base glass  1001 . The first adhesive layer  1004  is formed of, for example, a polymer adhesive or a rubber adhesive material. 
     An absorption coloring material  1005  is mixed in the first adhesive layer  1004 . The absorption coloring material  1005  may include a compound having a maximum absorption ratio at a wavelength between 550 and 580 nanometers. 
     One surface of a first base film  1006  is adhered to the surface of the first adhesive layer  1004  in which the absorption coloring material  1005  is mixed. A reflection preventive layer  1007  is formed on another surface of the first base film  1006 . A third base film  1010  is formed on a surface of the reflection preventive layer  1007 . 
     The electromagnetic wave shield filter  1002  includes a second base film  1011 , unlike the previous embodiment shown in  FIG. 9 , and an electromagnetic wave shield layer  1010  that is formed on one surface of the second base film  1011 , i.e., the surface of the second base film  1011  facing the first substrate  211 . The electromagnetic wave shield layer  1011  may be formed, for example, by patterning a fine metal mesh or oxidizing and stacking a transparent conductive film and a conductive metal layer. 
     A second adhesive layer  1012  is disposed between the base glass  1001  and the electromagnetic wave shield filter  1002  so that the electromagnetic wave shield filter  1002  is adhered to the base glass  1001 . 
       FIG. 11  is a partial cross-sectional view of a filter assembly  1100  according to another embodiment of the present invention. 
     Referring to  FIG. 11 , the filter assembly  1100  includes a base glass  1101 . An electromagnetic wave shield filter  1110  is formed on one surface of the base glass  1101 , i.e., the surface of the base glass  1101  facing the first substrate  211 . The electromagnetic wave shield filter  1110  is spaced apart from the first substrate  211  so that a gap g is formed between the filter assembly  1100  and the first substrate  211 . 
     An adhesive layer  1104  is formed on another surface of the base glass  1101 . The adhesive layer  1104  is formed of, for example, a polymer adhesive or a rubber adhesive material. Unlike the previous embodiments shown in  FIGS. 9 and 10 , an absorption coloring material  1105  is formed on the surface of the adhesive layer  1104 . 
     The absorption coloring layer  1105  may include a compound having a maximum absorption ratio at a wavelength between 550 and 580 nanometers. The absorption coloring layer  1105  may be formed of a compound of a cyanine derivative dye and an acryl derivative binder or a compound of a squarylium derivative dye and the acryl derivative binder. 
     The absorption coloring layer  1105  has a maximum absorption rate at a wavelength of a blue region corresponding to a wavelength between 490 and 500 nanometers, at a wavelength of a neon region corresponding to a wavelength between 590 and 600 nanometers, or at the wavelengths of the blue region corresponding to the wavelength between 490 and 500 nanometers and the neon region corresponding to the wavelength between 590 and 600 nanometers so as to absorb a luminescent spectrum. 
     A first base film  1106  is adhered to a surface of the absorption coloring layer  1105 . A reflection preventive layer  1107  is formed on another surface of the first base film  1106 . The reflection preventive layer  1107  is formed, for example, by stacking an AR film layer  1108  and an AG film layer  1109 . A second base film  1113  is formed on the surface of the reflection preventive layer  1107 . 
     In some embodiments, the absorption coloring material  1105  may be disposed between the base glass  1101  and the adhesive layer  1104  as shown in  FIG. 16 , may be disposed between the first base film  1106  and the reflection preventive layer  1107  as shown in  FIG. 17 , or may be disposed between the base glass  1101  and the electromagnetic wave shield filter  1110  as shown in  FIG. 18 , but the present invention is not limited thereto. 
       FIG. 12  is a partial cross-sectional view of a filter assembly  1200  according to another embodiment of the present invention. 
     Referring to  FIG. 12 , the filter assembly  1200  includes a base glass  1201 . An electromagnetic wave shield filter  1202  is formed on one surface of the base glass  1201 , i.e., the surface of the base glass  1201  facing the first substrate  211 . The electromagnetic wave shield filter  1202  is spaced apart from the first substrate  211  so that a gap g is formed between the filter assembly  1200  and the first substrate  211 . 
     A first adhesive layer  1204  is formed on another surface of the base glass  1201 . The first adhesive layer  1204  is formed of, for example, a polymer adhesive or a rubber adhesive material. An absorption coloring layer  1205  is formed on a surface of the first adhesive layer  1204 . 
     The absorption coloring layer  1205  may include a compound having a maximum absorption ratio at a wavelength between 550 and 580 nanometers. The absorption coloring layer  1205  may be formed of a compound of a cyanine derivative dye and an acryl derivative binder or a compound of a squarylium derivative dye and the acryl derivative binder. 
     One surface of a first base film  1206  is adhered to a surface of the absorption coloring layer  1205 . A reflection preventive layer  1207  is formed on another surface of the first base film  1206 . The reflection preventive layer  1207  is formed, for example, by stacking an AR film layer  1208  and an AG film layer  1209 . A third base film  1213  is adhered to a surface of the reflection preventive layer  1207 . 
     The electromagnetic wave shield filter  1202  includes a second base film  1211 , unlike the previous embodiment shown in  FIG. 11 . An electromagnetic wave shield layer  1210  is formed on one surface of the second base film  1211 , i.e., the surface of the second base film  1211  facing the first substrate  211 . A second adhesive layer  1212  is disposed between the base glass  1201  and the electromagnetic wave shield filter  1202  so that the electromagnetic wave shield filter  1202  is adhered to the base glass  1201 . 
     The display panel according to the above embodiments of the present invention provides the following effects. 
     First, the display panel has a minimum transmittance at a wavelength including a region of a green wavelength so that light having undesirable wavelength is absorbed, and a color reproduction of the display panel is increased. 
     Second, the display panel has a minimum transmittance at a wavelength of a region of a blue wavelength or a region of a neon wavelength, and a color purity of the display panel is increased. 
     Third, an absorption coloring material is mixed in an adhesive layer, or an absorption coloring layer is coated on the surface of the adhesive layer, so that undesirable wavelengths of the phosphor spectrum can be reduced, and the manufacturing of the display panel becomes less complicated. 
     While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill 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 and their equivalents. The exemplary embodiments should be considered in a descriptive sense only and not for purposes of limitation. Therefore, the scope of the present invention is defined not by the detailed description of the embodiments of the present invention but by the appended claims and their equivalents, and all differences within the scope will be construed as being included in the present invention.