KR20060027165A - Polarizer plate and liquid crystal display panel equipped the same - Google Patents

Abstract

The present invention attaches to both sides of a liquid crystal display panel to serve as a polarizer for selectively passing only light of a specific wavelength band, and at the same time, electrically separates the liquid crystal panel from the outside, thereby coupling according to electrical effects. The present invention relates to a liquid crystal panel polarizer plate and a liquid crystal panel having the same, which minimize noise, such as (coupling), and exhibit a blocking effect against electromagnetic interference.

To this end, the present invention specifically comprises a polarizing layer; First and second support layers attached to the lower surface of the polarizing layer; A polarizing plate for a liquid crystal panel comprising a transparent conductive layer interposed between an upper surface of the first support layer, the first support layer and the polarizing layer, between the polarizing layer and the second support layer, and a lower surface of the second support layer; Provided is a liquid crystal panel attached to both sides.

Polarizing layer, first and second support layer, transparent conductive layer, compensation layer

Description

Polarizing plate for liquid crystal panel and liquid crystal panel having same             

1 is a partial cross-sectional view of one pixel of a typical liquid crystal panel.

2 is a cross-sectional view showing an example of a general polarizing plate.

3 is a partial sectional view of one pixel of a liquid crystal panel according to the present invention;

4 is a cross-sectional view showing an example of a polarizing plate according to the present invention.

5 is a cross-sectional view showing an application example of the flat plate according to the present invention.

<Description of Symbols for Main Parts of Drawings>

110: first substrate 112: gate electrode

114: semiconductor layer 116: ohmic contact layer

118 source electrode 120 drain electrode

122: pixel electrodes 124, 138: first and second alignment layers

130: second substrate 132: black matrix

134: color filter 136: common electrode

140: liquid crystal layer 144: spacer

146: sealant 150a, 150b: first and second polarizing plates                 

152: adhesive layer 154: compensation layer

156: discotic liquid crystal film 158: wide view film

160,164: first and second support layers 162: polarizing layers

166: base layer 168: protective film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizer plate for a liquid crystal panel and a liquid crystal panel having the same. More specifically, a polarizer is attached to both sides of a liquid crystal panel to selectively pass only light having a specific wavelength. At the same time, the liquid crystal panel is electrically separated from the outside to minimize noise, such as coupling due to electrical effects, and exhibit a blocking effect against electromagnetic interference. A polarizing plate for a liquid crystal panel and a liquid crystal panel having the same.

In recent years, as the society enters the information age, the display field that processes and displays a large amount of information has been rapidly developed, and recently, the thin film transistor (Thin) having excellent performance of thinning, light weight, and low power consumption has recently been developed. Film Transistor (TFT) type liquid crystal display (TFT-LCD) has been developed to replace the existing cathode ray tube (CRT).                         

The image realization principle of such a liquid crystal display device uses optical anisotropy and polarization property of liquid crystal, and as is well known, liquid crystal has a thin and long molecular structure and optical anisotropy having an orientation in an array and is placed in an electric field. As a result, the direction of molecular arrangement changes according to its size.

The liquid crystal display is an essential component of a liquid crystal panel composed of a pair of transparent insulating substrates, each having a liquid crystal layer interposed therebetween and having a field generating electrode formed thereon. The liquid crystal panel includes two electrodes. By changing the electric field of the liver, the alignment direction of the liquid crystal molecules is artificially adjusted, and various images are displayed by the change of the transmittance of light.

Recently, in particular, an active matrix method in which thin-film transistors (TFTs) are provided in a one-to-one correspondence is provided so that pixels, which are the smallest unit of image expression, are arranged in a matrix manner. Matrix) Liquid crystal display devices are in the spotlight for their excellent resolution and ability to implement video.

More specifically, FIG. 1 is a cross-sectional view of a part of a general liquid crystal panel, and particularly, a cross-sectional view corresponding to one pixel.

Referring to this, a general liquid crystal panel is attached to the first and second substrates 10 and 30 facing each other, the liquid crystal layer 40 interposed therebetween, and the outer surfaces of the first and second substrates 10 and 30. And the first and second polarizers 50a and 50b to selectively pass only light of a specific wavelength.

In this case, although not clearly shown in the drawing on the inner surface of the first substrate 10 also referred to as an array substrate, the gate wirings and the data wirings are arranged in a matrix so that each pixel P is defined, and at the intersection thereof, the gate wirings and the data are defined. A thin film transistor T connected to the wiring is provided and connected to the pixel electrode 22 mounted in each pixel P. In this case, each of the thin film transistors T serves as a switching element for connecting the image signal transmitted through the data wiring to the pixel electrode 22 by the on / off signal transmitted through the gate wiring.

In addition, a black matrix 32 which prevents light leakage by covering a non-display area where liquid crystal alignment is impossible on the inner surface of the second substrate 30, which is called a color filter substrate, is interposed between an opening, that is, a display area, to display a specific color. An example of the display includes R, G, and B color filters 34 and a common electrode 36 interposed therebetween and facing the pixel electrode 22 with the liquid crystal layer 40 therebetween.

First and second alignment layers 24 and 38 are interposed between the liquid crystal layer 40, the pixel electrode 22, and the common electrode 36 to determine the initial arrangement direction of the liquid crystal molecules and to uniformly align the same. Spacers 44 are dispersed in the liquid crystal layer 40 to maintain a constant cell gap, and sealants 46 formed along edges of the first and second substrates 10 and 30 securely bond each other.

On the other hand, the general liquid crystal panel having the above-described structure is a light-receiving element that does not have a self-luminous element and thus requires a separate light source, and although not shown in the drawing, at least one fluorescent light is formed on the back of the liquid crystal panel. A separate back-light assembly is provided with an inverter means for controlling the lamp and its flashing to provide light.

Accordingly, the arrangement direction of the liquid crystal molecules 40 interposed therebetween is changed by the electric field difference between the pixel electrode 22 and the common electrode 36 for each pixel P, and the light generated from the backlight assembly is first polarized plate. The transmittance is determined while passing through the 50a, the liquid crystal layer 40, and the second polarizing plate 50b. During this process, the color of the pixel P is expressed by the color filter 34, thereby generating images of various colors. Is displayed.

On the other hand, the liquid crystal layer of the liquid crystal display device described above is mainly used the twisted nematic (TN) method, which has been spotlighted for providing excellent contrast and color reproducibility, but has a narrow viewing angle. I have a problem.

In addition, an additional compensation layer is additionally interposed to compensate for a phenomenon in which the luminance and contrast ratios differ depending on the viewing angles of the top, bottom, left, and right sides due to the difference in the anisotropic distribution of the liquid crystals. When laminated to the panel, the difference in light delay according to the viewing angle is reduced.

In this case, the compensation layer may be classified into various types according to its role and action, and unlike the nematic liquid crystal of the positive uniaxial medium in which the extraordinary refractive index is larger than the normal refractive index, the abnormal refractive index In addition to discotic liquid crystals, which are negative uniaxial, which are smaller than the normal refractive index, uni-axial films, bi-axial films, or wide view films, etc. In particular, such a compensation layer may be integrally formed with the first and second polarizing plates 50a and 50b, respectively, and attached to both sides of the liquid crystal panel.

2 is a cross-sectional view illustrating the polarizer 50 having the compensation layer 54, and includes, for example, a discotic liquid crystal film 56 and a wide view film 58. In this case, FIG. 2 is applicable to both the first and second polarization layers 50a and 50b of FIG. 1, and is represented by 50 for convenience.

In more detail, as shown, the polarizing plate 50 provided with the compensation layer 54 has an adhesive layer 52, a compensation layer 54, a first support layer 60, The polarizing layer 62, the second support layer 64, and the base layer 66 are sequentially provided. The double adhesive layer 52 may be a predetermined adhesive film used as a part bonded to the outer surface of one side of the liquid crystal panel. The compensation layer 54 may include, for example, a discotic liquid crystal film 56 and a wireless view film 58 as a part for improving a viewing angle characteristic according to the purpose.

In addition, the polarizing layer 64 is usually prepared by stretching a scratched polyvinyl alcohol (PVA) film in one direction and adsorbing iodine or dichroic dye, and the upper and lower surfaces thereof are each made of TAC (TriAcetyl Cellulose) or the like. The first and second support layers 60 and 64 are laminated to maintain the stretched state of the polarizing layer 62. And finally, the base layer 66 serves to protect the entire polarizing plate 50 as a portion exposed to the outside.

At this time, as shown, the lower portion of the adhesive layer 52 may include a separate protective layer 68, which is detached in the attaching process of the polarizer 50 to expose the adhesive layer 52, and the adhesive layer 52 in the process of transporting. ) Serves as a cover to protect against contamination.

Meanwhile, the general liquid crystal panel described with reference to FIG. 1 has a very weak characteristic against external electrical influences. As a specific example, the thin film transistor T is electrically affected when switching an inverter included in a backlight assembly. Coupling due to external electrical influences causes signal noise, called "Wavy noise," which causes a deterioration of image quality.

In addition, electromagnetic waves are emitted due to various electrical elements in the backlight assembly including the liquid crystal panel, and as a result, electromagnetic interference (Electro-Magnetic Interference: EMI) occurs.

Accordingly, the present invention has been made to solve the above problems, by electrically separating the liquid crystal panel so as to be free from external electrical influences to minimize the occurrence of various signal noises including coupling phenomenon, furthermore, electromagnetic waves It is an object of the present invention to provide a liquid crystal panel capable of blocking obstacles.

To this end, the present invention specifically provides a polarizing plate and a liquid crystal panel having the same, which can perform the above role.

The present invention and the polarizing layer to achieve the above object; First and second support layers attached to the lower surface of the polarizing layer; It provides a polarizing plate for a liquid crystal panel comprising a transparent conductive layer interposed between the upper surface of the first support layer, the first support layer and the polarizing layer, between the polarizing layer and the second support layer, the lower surface of the second support layer.

In this case, the polarizing layer is a scratched PVA film, the first and second support layers are each a TAC film, the transparent conductive layer is characterized in that ITO.

In addition, the present invention is a polarizing layer; First and second support layers attached to the lower surface of the polarizing layer; An adhesive layer attached to a lower surface of the second support layer; A base layer attached to an upper surface of the first support layer; And a transparent conductive layer interposed between the base layer and the first support layer, between the first support layer and the polarizing layer, between the polarizing layer and the second support layer, and between the second support layer and the adhesive layer. A polarizing plate for liquid crystal panels is provided.

In this case, the polarizing layer is a scratched PVA film, the first and the second support layer is characterized in that each is a TAC film.

And a compensation layer positioned between the second support layer and the adhesive layer, wherein the transparent conductive layer is between the base layer and the first support layer, between the first support layer and the polarizing layer, and between the polarizing layer and the first layer. It is characterized in that it is interposed between any one of the two support layer, between the second support layer and the compensation layer, between the compensation layer and the adhesive layer.

In particular, the compensation layer includes at least one selected from a uniaxial film, a biaxial film or a wide view film or a discotic liquid crystal film or at least one selected from the uniaxial film, a biaxial film or a wide view film and a discotic liquid crystal film. In this case, the transparent conductive layer is between the base layer and the first support layer, between the first support layer and the polarizing layer, between the polarizing layer and the second support layer, between the second support layer and the compensation layer And at least one selected from the uniaxial film, the biaxial film, or the wide view film and the discotic liquid crystal film, and any one of the compensation layer and the adhesive layer.

And the transparent conductive layer is characterized in that the ITO.

In addition, the present invention is a liquid crystal panel having a polarizing plate described above, the first and second substrates facing each other with a liquid crystal layer interposed therebetween with the polarizing plates attached to their respective outer surfaces; Gate and data lines arranged along the inner surface of the first substrate to define pixels; A pixel electrode mounted on each pixel; A thin film transistor including a semiconductor layer, a gate electrode connected to the gate wiring, a source electrode connected to the data wiring, and a drain electrode connected to the pixel electrode; A black matrix covering edges of the thin film transistor and the pixel electrode along an inner surface of the second substrate; A color filter filled with an opening of the black matrix; The present invention provides a liquid crystal panel comprising a common electrode covering the black matrix and the color filter. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a cross-sectional view showing a part of the liquid crystal panel according to the present invention, in particular one pixel structure.

As can be seen, the liquid crystal panel according to the present invention includes first and second substrates 110 and 130 bonded to each other with the liquid crystal layer 140 interposed therebetween. In this case, the first and second substrates 110 and 130 are typically made of a transparent insulating material such as glass, and may be made of plastic or the like, depending on the purpose.

The pixel P is defined by crossing the gate line and the data line on the inner surface of the first substrate 110, and the pixel electrode 122 is mounted on each pixel P. FIG. In addition, a thin film transistor T, which is a switching element, is provided at an intersection point of the gate wiring and the data wiring so as to be connected to each pixel electrode 122 one-to-one. ), An island-like semiconductor layer 114 covering the same, and an ohmic contact layer 116 containing impurities to provide a channel (ch), which is a movement path of charge or hole, and a gate electrode 112 thereon, respectively. And a drain electrode 120 connected to the pixel electrode 122 and a source electrode 118 spaced apart from each other so as to overlap each other.

In addition, a black matrix is formed on the inner surface of the second substrate 130 to suppress light leakage by covering a non-display area irrelevant to the liquid crystal driving, such as the thin film transistor T, the gate wiring, and the data wiring. 132 and an example of R, G, and B color filters 134 interposed corresponding to the openings thereof, that is, the display area, respectively, and cover the black matrix 132 and the color filter 134 to form a liquid crystal. The common electrode 136 is provided to face the pixel electrode 122 with the layer 140 interposed therebetween.

At this time, between the liquid crystal layer 140, the pixel electrode 122, and the common electrode 136, each made of a polyimide organic polymer material of about several hundred micrometers, respectively, and the surfaces facing the liquid crystal are rubbing in a predetermined direction, respectively. The first and second alignment layers 124 and 138 interposed therebetween to uniformly align the initial alignment state and the alignment direction of the liquid crystal molecules, and the spacer 144 to the liquid crystal layer 140 interposed between the first and second substrates 110 and 130. ) Is dispersed to maintain a constant cell gap, and the sealants 146 adhere to each other at edges of the first and second substrates 110 and 130 provided with these components, and prevent leakage of the liquid crystal layer 140.

In addition, the first and second polarizing plates 150a and 150b according to the present invention are attached to the outer surfaces of the first and second substrates 110 and 130, respectively, to selectively pass only light that vibrates in a specific direction.

On the other hand, such a liquid crystal panel is provided with a backlight assembly including a plurality of fluorescent lamps or an inverter for controlling their blinking as a separate external light source to supply light.

Accordingly, when the on / off signal of the thin film transistor T is applied to the gate line, the thin film transistor T transfers the pixel signal of the data line to the selected pixel electrode 122. Accordingly, the pixel electrode 122 is generated. The arrangement direction of the liquid crystal molecules interposed therebetween is artificially adjusted due to the electric field difference between the common electrode 136 and the common electrode 136, while passing through the first polarizing plate 150a, the liquid crystal layer 140, and the second polarizing plate 150b. The transmittance of light is determined, and the color according to the transmittance appears as it passes through the color filter 134.

In this case, the liquid crystal layer 140 may be any type as long as the first and second polarization layers 150a and 150b are interposed on both sides of the liquid crystal panel, for example, twisted nematic or super twisted nematic mode (STN). In addition, various types may be used according to purposes such as a vertical alignment mode (VA) and an in plane switching mode.

That is, the liquid crystal panel according to the present invention is characterized in that the first and second polarizing layers 150a and 150b which are attached to both surfaces thereof to pass only light in a specific wavelength band, and the scope of application of the present invention is Applicability to a kind of liquid crystal panel can be easily understood by those skilled in the art through the following description. Hereinafter, the first and second polarization layers 150a and 150b, which are features of the present invention, will be described in detail.

4 is a cross-sectional structural view showing the simplest example of the polarizing plate 150 according to the present invention. For convenience, the first and second polarizing plates 150a and 150b are represented by the reference numeral 150.

The polarizing plate 150 according to the present invention includes first and second support layers 160 and 164 attached to upper and lower surfaces thereof with a polarizing layer 162 interposed therebetween, and between the first support layer 160 and the polarizing layer 162. Alternatively, the transparent conductive layer 170 interposed between the polarizing layer 162 and the second support layer 164 is an essential component.

In other words, the present invention is characterized in that the transparent conductive layer 170 is interposed in the polarizing plate 150 of the multilayer structure in which different heterogeneous materials including the polarizing layer 162 are stacked, wherein the transparent conductive layer 170 is ITO (Indium). Tin Oxide) and the like.

As is well known, ITO is representative of a transparent conductive material. As the polarizing plate 150 having the transparent conductive layer 170 is attached to both sides of the liquid crystal panel, the liquid crystal panel may be electrically separated and free from external influences. As a result, coupling or other signal noise of the thin film transistor (T) due to the inverter of the backlight assembly can be prevented.

Therefore, as long as the transparent conductive layer 170 performs the above-described role, it is also possible to use a transparent polymer compound in addition to ITO, and electrically maintains a grounded state.

The polarizing layer 162 may be prepared by drawing a scratched PVA film in one direction and adsorbing iodine or a dichroic dye, and laminating the upper and lower surfaces thereof to maintain the stretched state of the polarizing layer 162. The first and second support layers 160 and 164 may each be made of TAC, and if necessary, the transparent conductive layer 170 may serve as one support layer, and thus the second support layer 164 may be omitted in the drawing.

On the other hand, Figure 4 is presented as shown in the simplest example to show the features of the present invention as best described above, in addition to the form of a polarizing plate 150 including a compensation layer 154 as shown in Figure 5 is possible Bar, this is also only one application of the present invention, of course, can be modified as many as long as the technical spirit of the present invention.

As shown therein, FIG. 5 is a cross-sectional view of a polarizing plate 150 in which a compensation layer 154 is integrated to improve viewing angle characteristics, and the first and second support layers attached to both surfaces thereof with a polarizing layer 162 interposed therebetween. Compensation layer 154 interposed on the lower surface of the first support layer 160, including (160,164).

In this case, the compensation layer 154 may include at least one selected from a uniaxial film or a biaxial film including the discotic liquid crystal film 156 or the wide view film 158, or both of them may be used according to the purpose. It can be variously modified.

In addition, a predetermined adhesive layer 152 may be disposed on the lower surface of the compensation layer 154 so that the polarizing plate 150 may be attached to both sides of the liquid crystal panel, and the liquid crystal panel is separately formed on the outer surface of the second support layer 164. When attached to the adhesive layer 152 is provided with a base layer 166 in the form of a film to form an exposed surface to be exposed to the outside to protect the entire polarizing plate 150. In addition, a separate protective film 168 may be attached to an outer surface of the polarizing plate 150 in order to prevent the adhesive layer 152 from being contaminated during transportation and transport, thereby reducing the adhesive strength.

On the other hand, in this case, the transparent conductive layer 170 may be interposed between the layers as shown in the appropriate position between the layers, specifically, between the base layer 166 and the second support layer 164, the second support layer Between the 164 and the polarizing layer 162, between the polarizing layer 162 and the first support layer 160, between the first support layer 160 and the compensation layer 154, the compensation layer 154 and the adhesive layer 152 It may be interposed between any one of), and depending on the purpose, it is also possible to intervene between the compensation layer 154, in particular between the discotic liquid crystal film 156 and the wide view film 158.

In summary, the liquid crystal panel is electrically separated from the outside by interposing transparent conductive layers 170 in polarizing plates 150 that are attached to both sides of the liquid crystal panel to selectively pass only light having a specific wavelength. According to the type of the polarizing plate 150, the position of the transparent conductive layer 170 can be free as much as possible, according to the unique role of the polarizing plate 150 and the signal noise phenomenon such as coupling due to the external electrical influence Of course, it is possible to provide a variety of other functions, including the compensation layer 154 to minimize the electromagnetic interference, and also to improve the viewing angle.

Accordingly, the liquid crystal panel according to the present invention is electrically separated from the outside, and thus can be free from external electric influences. In particular, the liquid crystal panel according to the present invention minimizes signal noise caused by the coupling phenomenon of the thin film transistor due to the inverter of the backlight assembly. Can be reduced.

Therefore, there is an advantage that more improved image realization is possible.

In addition, the liquid crystal panel according to the present invention exhibits an excellent electromagnetic wave blocking effect, and thus may be safely used.

Claims (12)

A polarizing layer; First and second support layers attached to the lower surface of the polarizing layer; And a transparent conductive layer interposed between the upper surface of the first support layer, the first support layer and the polarizing layer, between the polarizing layer and the second support layer, and the lower surface of the second support layer. The method of claim 1, The polarizing layer is a scratched PVA film, the first and second support layer is a liquid crystal panel polarizing plate, characterized in that each is a TAC film. The method according to claim 1 or 2, wherein The transparent conductive layer is ITO polarizing plate, characterized in that the. A polarizing layer; First and second support layers attached to the lower surface of the polarizing layer; An adhesive layer attached to a lower surface of the second support layer; A base layer attached to an upper surface of the first support layer; And a transparent conductive layer interposed between the base layer and the first support layer, between the first support layer and the polarizing layer, between the polarizing layer and the second support layer, and between the second support layer and the adhesive layer. A polarizing plate for liquid crystal panels. The method of claim 4, wherein The polarizing layer is a scratched PVA film, the first and second support layer is a liquid crystal panel polarizing plate, characterized in that each is a TAC film. The method of claim 4, wherein Further comprising a compensation layer located between the second support layer and the adhesive layer, In this case, the transparent conductive layer is between the base layer and the first support layer, between the first support layer and the polarizing layer, between the polarizing layer and the second support layer, between the second support layer and the compensation layer, and the compensation layer. And interposed between any one of the adhesive layer, the polarizing plate for a liquid crystal panel. The method of claim 6, The compensation layer is a polarizing plate for a liquid crystal panel, characterized in that at least one selected from uniaxial film, biaxial film or wide view film. The method of claim 6, The compensation layer is a liquid crystal panel polarizing plate comprising a discotic liquid crystal film. The method of claim 6, The compensation layer includes at least one selected from a uniaxial film, a biaxial film or a wide view film and a discotic liquid crystal film, In this case, the transparent conductive layer is between the base layer and the first support layer, between the first support layer and the polarizing layer, between the polarizing layer and the second support layer, between the second support layer and the compensation layer, and the uniaxiality. And at least one selected from a film, a biaxial film, or a wide view film and a discotic liquid crystal film, and one of the compensation layer and the adhesive layer. The method according to any one of claims 4 to 9, wherein The transparent conductive layer is ITO polarizing plate, characterized in that the. A liquid crystal panel provided with the polarizing plate according to any one of claims 4 to 8, First and second substrates facing each other with a liquid crystal layer interposed therebetween with the polarizers attached to respective outer surfaces thereof; Gate and data lines arranged along the inner surface of the first substrate to define pixels; A pixel electrode mounted on each pixel; A thin film transistor including a semiconductor layer, a gate electrode connected to the gate wiring, a source electrode connected to the data wiring, and a drain electrode connected to the pixel electrode; A black matrix covering edges of the thin film transistor and the pixel electrode along an inner surface of the second substrate; A color filter filled with an opening of the black matrix; And a common electrode covering the black matrix and the color filter. The method of claim 11, The transparent conductive layer of the polarizing plate is a liquid crystal panel, characterized in that ITO.

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