KR100781263B1 - Front Filter of Plasma Display Panel - Google Patents

Abstract

The present invention relates to a plasma display panel (hereinafter referred to as "PDP").

The present invention provides a front filter for a plasma display panel (PDP) comprising an electromagnetic shielding film comprising a conductive powder, a solvent, a binder, and a dispersant.

Therefore, according to the present invention, it is possible to provide a front filter for PDP having excellent conductivity and excellent light transmittance.

PDP, front filter, EMI shield, CNT

Description

Front filter of plasma display panel {Front Filter of Plasma Display Panel}

1 is a cross-sectional view of a plasma display panel (PDP).

Fig. 2A is a sectional view of the glass type front filter for PDP.

Figure 2b is a cross-sectional view of the film type front filter for PDP.

Figure 3a is a view showing the structure of the EMI shielding film according to the prior art.

3B is a cross sectional view taken along the line II ′ of FIG. 3A;

Figure 4 is a cross-sectional view of the EMI shielding film of the front filter for PDP according to the present invention.

5 is a cross-sectional view of a front filter for a PDP including an adhesive layer having an electromagnetic shielding function according to the present invention;

<Explanation of symbols for the main parts of the drawings>

10: lower plate glass 20: base film

30: address electrode 40: lower plate dielectric

50: bulkhead 55: black matrix

60: phosphor 70: top glass

73: sustain electrode 76: bus electrode

80: top dielectric 85: protective film

90: discharge gas 100: PDP lower plate

150: PDP top plate 200: color correction film

210: NIR shielding film 220: EMI shielding film

230: glass 240: AR film

300: base film 305: frame

310: conductive mesh 400: base film

410: electromagnetic wave shielding layer 420: conductive powder

500: color correction film 510: first adhesive layer

520: NIR shielding film 530: second adhesive layer

540: EMI shielding film 550: third adhesive layer

560: AR film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel (PDP), which is one of new image display devices in the multimedia era, and more particularly to a front filter of a PDP.

With the advent of the multimedia era, display devices that can express more detailed, larger, and more natural colors are required.

However, there is a limit to the current CRT (Cathode Ray Tube) structure or LCD (Liquid Crystal Display) method to construct a large screen of 40 inches or more, and PDP is attracting attention among flat panel display devices, and its use is expanding to the field of high-quality video. For the sake of this, high-definition and large screens are rapidly developing.

The biggest feature of PDP is that it can be made as thin as 10cm or less compared to the same self-luminous CRT, and it is easy to manufacture large flat screen (60 ~ 80inch), and also in terms of style and design, it is different from conventional CRT. It is clearly distinguishable.

PDP is thin, light, self-luminous and enables real-time, realistic images, simple structure, and easy to produce large-screen flat panel display, and has been qualified for HDTV (high definition TV) since early.

Compared with LCD, it is a self-luminous type, so you can see beautiful and beautiful screens over a wide range of left and right.

Especially, since the screen replacement time is 10 times faster than LCD, it is the most suitable TV for displaying moving images.It is bright because it is a video display method in a fixed pixel by dot matrix method, and color deviation and screen skew Without the influence of the magnetic field at all, it can be said to be the best TV for a large screen, high-definition video.

The PDP has a phosphor in a pixel defined by a partition wall, and includes a lower plate having an address electrode at each lower portion of the phosphor, and an upper plate having a bus electrode and a sustain electrode opposed to the address electrode of the lower plate.

1 is a cross-sectional view of the PDP.

Referring to Figure 1, the structure of the PDP according to the prior art will be described.

1 is a cross-sectional view of a conventional PDP, wherein an underlayer 20 is positioned on an upper portion of the lower plate glass 10, and an address electrode 30 is positioned on a portion of an upper portion of the underlayer 20. The lower dielectric 40 is positioned on the upper surface of the address electrode 30.

The upper part of the lower plate dielectric 40 is formed with a partition wall 50. The partition wall 50 has a longer vertical direction than a horizontal direction and is spaced apart from the address electrode 30 by a predetermined distance.

A black matrix 55 is positioned on an upper surface of the partition 50, and a phosphor 60 is positioned on the side surfaces of the black matrix 55 and the partition 50 and an upper surface of the lower plate dielectric 40. .

The above is the structure of the PDP lower plate 100 and the structure of the PDP upper plate 150 will be described below.

The sustain electrode 73 and the bus electrode 76 are sequentially stacked on the lower surface of the upper plate glass 70, and the upper plate dielectric is formed on the lower surface of the upper plate glass 70, the sustain electrode 73 and the bus electrode 76. 80) is located.

A protective film 85 is positioned on a lower surface of the upper dielectric 80, and the protective film 85 is formed parallel to the upper dielectric 40 and spaced apart from the upper surface of the black matrix 55 by a predetermined distance. The upper and lower panels of PDP are combined.

At this time, the discharge gas 90 is injected into the discharge cells defined by the PDP upper plate 150, the lower plate 100, and the partition wall 50. The discharge gas 90 is He-Xe or Ne- as an inert gas. Xe or He-Ne-Xe gas or the like is injected.

The operation of the conventional plasma display panel described above is as follows.

When a voltage is applied to the address electrode 30, the bus electrode 76, and the sustain electrode 73 to generate a voltage difference between the upper plate and the lower plate electrodes, the voltage difference is formed in the discharge cell defined as the partition wall 50, the upper plate, and the lower plate. A gas such as He-Xe, Ne-Xe, or He-Ne-Xe, which is a discharge gas 90, becomes a plasma state and ultraviolet rays are generated.

The generated ultraviolet rays excite the phosphor 60 to generate red, green, or blue visible light. The generated visible light is determined according to the type of the phosphor 60. Accordingly, each of the discharge cells It is red, green or blue.

The generated visible light is emitted to the outside through the transparent top dielectric 80 and the top glass 70.

The upper plate dielectric 80 is in direct contact with the sustain electrode 73 using the transparent electrode ITO and the bus electrode 76 serving as the metal electrode, and thus the chemical reaction between the sustain electrode 73 and the bus electrode 76 is performed. PbO-based glass with high softening point is used to avoid.

The top dielectric 80 and the top glass 70 serve to transmit visible light generated from the phosphor 60 with a predetermined transmittance.

The upper surface of the upper plate 150 of the PDP having the structure as described above is provided with a front filter to block the electromagnetic wave and reflect the light incident from the outside.

2A and 2B are sectional views showing a conventional front filter for PDP.

Referring to FIGS. 2A and 2B, a conventional front filter for a PDP is as follows.

FIG. 2A is a cross-sectional view of a glass type front filter, and a NIR (Near Infrared Rays) shielding film 210 is provided on an upper surface of the color correction film 200, and an EMI is provided on an upper surface of the NIR shielding film 210. FIG. (ElectroMagnetic Interference, electromagnetic wave) shielding film 220 is provided, the glass 230 is provided on the EMI shielding film 220, the AR film (Anti-Reflection film, anti-reflection film) on the glass 230 240 is provided.

The glass 230 is for preventing the front filter from being damaged from an external impact, but the glass type front filter has a disadvantage that the thickness is thick, the weight is heavy, and the manufacturing cost is increased.

Therefore, the film type front filter of FIG. 2B has been proposed. The film type front filter has the same basic configuration as the glass type front filter, but does not include the glass 230.

Referring to Figures 3a and 3b will be described the structure of the EMI shielding film according to the prior art as follows.

EMI shielding film according to the prior art is provided with a conductive mesh (Mesh, 310) on the upper surface of the base film 300, the conductive mesh 310 is supported by the frame 305.

The conductive mesh 310 is formed by patterning a metal layer using silver (Ag), copper (copper), indium tin oxide (ITO), or the like by a photolithography process and an etching process. The electrode lines have a structure in which they cross each other.

In detail, a metal thin film is formed on the base film 300, and a photoresist is coated on the metal thin film.

Subsequently, the photoresist is patterned using a mask to form a photoresist pattern in the form of a frame and a mesh.

By patterning the metal thin film using the photoresist pattern as a mask, a frame 305 and a conductive mesh 310 are formed on the base film 300 as shown in FIG. 3B, and the remaining photoresist pattern is stripped. Removed.

However, the EMI shielding film of the conventional PDP front filter has the following problems.

First, when the front filter including the EMI shielding film formed of well-expanded copper, silver, ITO, etc. is bonded to the PDP, the lattice gap is shifted or the lattice pattern is deformed so that visible light transmittance is inhibited.

Second, when the angle formed by a plurality of intersecting electrode lines having a mesh structure is different, the productivity is poor because it must be changed from the design value of the photolithography process.

Third, due to the photolithography process and the process for patterning the metal thin film, the loss of materials and the number of processes are complicated.

The present invention is to solve the above problems, an object of the present invention is to provide an EMI shielding film excellent in conductivity and light transmittance.

An object of the present invention is to provide an EMI shielding film which is excellent in productivity due to low material loss in the manufacturing process and a simple process number.

In order to achieve the above object, the present invention provides a front filter for a plasma display panel (PDP) comprising an electromagnetic shielding film comprising a conductive powder, a solvent, a binder and a dispersant.

According to another embodiment of the present invention, there is provided a front filter for a PDP comprising an adhesive layer containing a conductive powder, a solvent, a binder, and a dispersant.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

A first embodiment of a front filter for a PDP according to the present invention will be described with reference to FIGS. 4 and 5 as follows.

The basic configuration of the first embodiment is the same as that of the conventional front filter, but is different from the conventional electromagnetic shielding film in that the EMI shielding film includes conductive powder, a solvent, a binder, and a dispersant.

The conductive powder should be a low-resistance material, copper, silver, gold, nickel, aluminum, platinum, etc., preferably made of carbon nanotubes (CNT).

CNT is a material having excellent conductivity, and the CNTs should be uniformly dispersed in the electromagnetic shielding film so that the CNT film is entirely connected to maintain conductivity.

The solvent may be a solvent such as alcohol, erre, aromatic, benzene, and the like, and the dispersant should be affinity for the solvent and the binder.

As the binder, a binder such as acrylic or cellulose, which can be dissolved in the solvent, should be used.

In order to satisfy the characteristics, as shown in FIG. 4, the solution including the CNT powder 420 on the base film 400 should form the electromagnetic wave blocking layer 410, and the electromagnetic wave blocking layer 410 It is preferably formed by the method of coating.

When the solution containing the CNT powder 420 is coated on a film or glass, the CNT film must be connected to maintain overall conductivity through proper dispersion, and form a fiber network by forming a networking at an appropriate content. Permeability must also be maintained.

Therefore, the dispersion of the CNT powder in the solution including the CNT powder 420 is the most important factor, and for this purpose, proper mixing of the CNT powder, the solvent, the dispersant and the binder is necessary.

As the content of the CNT powder 420 increases in the solution including the CNT powder 420, the conductivity is improved, but the light transmittance is decreased, so that the content of the CNT powder 420 is appropriately selected according to the required resistance and light transmittance. Should be adjusted.

In general, in order to use the front filter for the PDP, the electromagnetic shielding film preferably maintains a light transmittance of 60 to 90%.

In order to maintain the light transmittance, in the solution containing the CNT powder 420, the CNT powder 420 has a weight ratio of 0.5 to 20%, the binder is 1 to 20% by weight, and the dispersant is 1 to 5 of the CNT powder It is preferably included in the weight ratio of%.

In addition, the CNT powder may have a diameter of several nm to several tens of nm, but may be manufactured to be 380 nm or less, which is a wavelength range of visible light, to secure transmittance of visible light from the PDP.

Coating the solution containing the CNT powder 420 blended in the weight ratio on top of the base film 400 by using a coating machine such as Micro Gravure Coater, and heat-treating materials other than the CNT powder 420 Can be removed.

The solution containing the CNT powder 420 may be coated on the base film 400 made of PET or TAC and used as a part of a front filter for a PDP. In the case of a glass filter, the solution may be directly coated on glass. It can also be coated directly on the top of the PDP.

5 is a cross-sectional view of a front filter for a PDP including an adhesive layer having an electromagnetic shielding function according to the present invention.

The front filter for PDP including the electromagnetic shielding film is provided with a NIR shielding film 520 on the top of the color correction film 500, the electromagnetic shielding film 540 is provided on the NIR shielding film, AR on the upper portion of the electromagnetic shielding film The film 560 is provided, and in the case of a glass filter, glass is further provided between the electromagnetic shielding film 540 and the AR film 560.

A first adhesive layer 510 is provided between the color correction film 500 and the NIR shielding film 520, and a second adhesive layer 530 is disposed between the NIR shielding film 520 and the electromagnetic shielding film 540. ) Is provided, and a third adhesion layer 550 is provided between the electromagnetic shielding film 540 and the AR film 560.

The AR film 560 is located on the surface of the front filter and prevents light incident from the outside from being reflected back to the outside to improve the contrast of the display panel, and is further formed on the rear surface of the front filter. Can be.

The lower portion of the AR film is provided with the electromagnetic shielding film 540 to shield the electromagnetic interference (Electromagnetic Interference) to prevent the EMI incident from the display panel to be emitted to the outside.

The NIR shielding film 520 is provided under the electromagnetic shielding film 540 to shield NIR (Near Infrared Rays) above a reference value emitted from a display panel, and uses IR (Infrared Rays) such as a remote control to provide a signal. Allowing devices to deliver signals normally.

The color correction film 500 is provided below the NIR shielding film 520 to reduce the brightness of red and green light and increase the brightness of blue of the light incident from the front of the display panel, thereby improving the optical characteristics of the display panel. Improve.

A second embodiment of the PDP front filter according to the present invention will be described below.

In the second embodiment, the conductive powder is dispersed in at least one of the first, second, and third adhesive layers 510, 530, and 550 to shield electromagnetic waves.

In other words, unlike the first embodiment, since the electromagnetic shielding function is performed in the first, second, and third adhesive layers 510, 530, and 550, the electromagnetic shielding film 540 may not be provided separately.

As in the first embodiment, in the adhesive layer, the CNT powder 420 may include a weight ratio of 0.5 to 20%, a binder ratio of 1 to 20%, and a dispersant in a weight ratio of 1 to 5% of the CNT powder. do.

In addition, the CNT powder may have a diameter of several nm to several tens of nm, but may be manufactured to be 380 nm or less, which is a wavelength range of visible light, to secure transmittance of visible light from the PDP.

The present invention is not limited to the above-described embodiments, and such modifications are included within the scope of the present invention even though modifications may be made by those skilled in the art to which the present invention pertains.

The effects of the front filter of the plasma display panel according to the present invention described above are as follows.

The front filter for PDP according to the present invention is excellent in conductivity and light transmittance because the CNT powder is dispersed in the electromagnetic shielding film.

The front filter for PDP according to the present invention has less material loss in the manufacturing process and has a simpler process number than the conventional technology, and thus has excellent productivity.

Claims (11)

Conductive powder, a binder, a dispersant and a solvent, Here, the conductive powder has a weight ratio of 0.5 to 20% in the front filter, the binder has a weight ratio of 1 to 20% in the front filter, and the dispersing agent has a weight ratio of 1 to 5% of the conductive powder. And a front filter of the plasma display panel. The method of claim 1, wherein the conductive powder, The front filter of the plasma display panel, characterized in that the carbon nanotubes. The method of claim 1, The conductive powder, the binder, the dispersant, and the solvent are provided on the base film to form an electromagnetic wave shielding layer. The method of claim 1, The conductive powder, the solvent, the dispersant, and the solvent form an adhesive layer. The method according to claim 1 or 4, The conductive powder, the solvent, the dispersant, and the solvent are directly formed on the substrate of the plasma display panel. delete The method of claim 1, wherein the conductive powder, A front filter of a plasma display panel, the diameter of which is 380 nanometers or less. The method of claim 1, The front filter of the plasma display panel further comprises an anti-reflection film. The method of claim 1, The front filter of the plasma display panel further comprises an optical characteristic film. The method of claim 1, A front filter of a plasma display panel, further comprising a near infrared shielding film. delete

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