Patent Application
20090220798
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.
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
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.
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.
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:
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.
Referring to
Referring to
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
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]
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
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)O4;Eu, the green phosphor layer may be formed of YAl3(BO3)Tb, and the blue phosphor layer may be formed of BaMgAl10O17:Eu. Alternatively, the blue phosphor layer may be formed of CaMgSi2O6:Eu or a compound of BaMgAl10O17:Eu and CaMgSi2O6: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)O4;Eu, the green phosphor layer formed of YAl3(BO3)Tb, and the blue phosphor layer formed of BaMgAl10O17: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
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.
The phosphor layer includes the red phosphor layer formed of Y(P,V)O4;Eu, the green phosphor layer formed of YAl3(BO3)Tb, and the blue phosphor layer formed of BaMgAl10O17:Eu.
Referring to
Referring to
Referring to
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
Referring to
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.
Referring to
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
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.
Referring to
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
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
Referring to
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
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2008-0019619 | Mar 2008 | KR | national |
