KR20120119111A - Light leakage free liquid crystal display device with large size and thin thickness - Google Patents

Abstract

PURPOSE: A light leakage free liquid crystal display device is provided to control a bending direction of a liquid crystal panel by designing the contraction rates of polarization plates of upper/lower substrates to reduce the degree of bending the liquid crystal panel, thereby reducing light leakage. CONSTITUTION: An upper polarization plate(101) and a lower polarization plate(111) have phase difference films, protective films, and adhesives. The protective films are laminated on both sides of the phase difference films. The adhesives are bonded with a liquid crystal panel. A backlight unit(140) is installed on a rear side of the liquid crystal panel. The backlight unit emits light onto the entire surface of the liquid crystal panel. A case component couples the liquid crystal panel with the backlight unit.

Description

LIGHT LEAKAGE FREE LIQUID CRYSTAL DISPLAY DEVICE WITH LARGE SIZE AND THIN THICKNESS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having improved light leakage due to an increase in size and thickness of a liquid crystal display device.

2. Description of the Related Art In general, a liquid crystal display device is a display device which can display a desired image by individually supplying data signals according to image information to pixels arranged in a matrix form and adjusting light transmittance of the pixels.

Accordingly, the liquid crystal display includes a liquid crystal panel in which pixels are arranged in a matrix and a driving unit for driving the pixels.

The liquid crystal panel is composed of a color filter substrate, an array substrate, and a liquid crystal layer formed in a cell gap between the color filter substrate and the array substrate so as to face each other to maintain a uniform cell gap. do.

In this case, a common electrode and a pixel electrode are formed in the liquid crystal panel to which the color filter substrate and the array substrate are bonded to apply an electric field to the liquid crystal layer.

Therefore, when the voltage of the data signal applied to the pixel electrode is controlled while the voltage is applied to the common electrode, the liquid crystal of the liquid crystal layer rotates by dielectric anisotropy according to the electric field between the common electrode and the pixel electrode. Characters or images are displayed by transmitting or blocking light for each pixel.

In this case, since the liquid crystal display does not emit light by itself and is a light-receiving element that displays an image by adjusting the transmittance of light coming from the outside, a separate device for irradiating light to the liquid crystal panel, that is, a backlight unit is provided. Required.

Hereinafter, a general liquid crystal display device will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view schematically illustrating a structure of a general liquid crystal panel, and FIG. 2 is a cross-sectional view schematically illustrating a general liquid crystal display device.

First, as shown in FIG. 1, a general liquid crystal panel includes a color filter substrate 5 and an array substrate 10, and a liquid crystal layer 30 formed between the color filter substrate 5 and the array substrate 10. It consists of.

The color filter substrate 5 includes a color filter C composed of a plurality of sub-color filters 7 for implementing colors of red (R), green (G), and blue (B); A black matrix 6 that separates the sub-color filters 7 and blocks light passing through the liquid crystal layer 30, and a transparent common electrode that applies a voltage to the liquid crystal layer 30. 8)

In addition, the array substrate 10 may be arranged vertically and horizontally to define a plurality of gate lines 16 and data lines 17 defining a plurality of pixel regions P. The thin film transistor T, which is a switching element formed in the cross region, and the pixel electrode 18 formed on the pixel region P, are formed.

As shown in FIG. 2, the liquid crystal panel configured as described above is provided at a rear surface of the liquid crystal panel, and a guide unit which fixes and couples the liquid crystal panel and the backlight unit to each other and emits light over the entire surface of the liquid crystal panel. A liquid crystal display device may be configured by including case parts such as a panel 24, an upper case 21, and a lower cover 22.

In this case, the backlight unit will be described in detail. A light emitting diode (LED) array 45 generating light on the lower cover 22 and an LED printed circuit board driving the LEDs. A PCB (not shown) and a reflecting plate 43 are provided, and the light guide plate 42 is installed in the light exit direction of the LED array 45.

A lamp housing 23 secures the LED array 45 and the LED printed circuit board.

Light generated by the LED array 45 is incident on the side of the light guide plate 42 of a transparent material, and the reflecting plate 43 disposed on the rear surface of the light guide plate 42 is transmitted to the rear surface of the light guide plate 42. The light is reflected toward the optical sheets 41 on the upper surface of the light guide plate 42 to reduce light loss and improve uniformity.

A liquid crystal panel including the color filter substrate 5 and the array substrate 10 is seated on the upper portion of the backlight unit configured as described above, and is coupled to each other through adhesive tapes 15a and 15b and the upper case 21 to form a liquid crystal display device. Will be constructed.

In this case, upper and lower polarizers 1 and 11 are attached to the outer surfaces of the color filter substrate 5 and the array substrate 10, respectively, and the upper polarizer 1 polarizes light passing through the liquid crystal panel. The lower polarizer 11 polarizes light via the optical sheets 41.

On the other hand, as the display industry develops, the demand for larger and thinner displays is increasing. In this case, in the case of a large-sized liquid crystal display device, light leakage occurs at four corners due to a decrease in the degree of freedom of bending of the liquid crystal panel due to a structural change. That is, light leakage occurs due to the deformation of the liquid crystal array due to the depressing of the mechanism due to the decrease in the degree of bending freedom of the liquid crystal panel (part A of FIG. 2). In particular, in the case of an in-plane switching (IPS) type liquid crystal display device, since liquid crystals are arranged in a horizontal direction, they have a sensitive characteristic such as an upper case.

In addition, as the liquid crystal display becomes thinner, a light leakage problem due to instrument interference occurs due to a decrease in the margin between the liquid crystal panel and the instrument.

In the past, there are several known ways to improve light leakage.

First, there is a method of minimizing the shrinkage stress applied to the liquid crystal panel by minimizing the shrinkage stress generated in the polarizer.

Second, there is a method of reducing the deformation caused by heat by increasing the molecular density of the adhesive resin (resin).

Third, there is a method of securing thermal stability by increasing crosslinking degree between chains by adding functional groups between chains of base film resin.

However, in the conventional case, the exact cause for light leakage improvement has not been made, and only a partial solution is presented, and thus, when the structure is changed, it is not easy to respond.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device for improving light leakage due to the increase in size and thickness of the liquid crystal display device.

Other objects and features of the present invention will be described in the following description of the invention and claims.

In order to achieve the above object, the liquid crystal display device of the present invention comprises a liquid crystal panel formed between the color filter substrate and the array substrate to output an image; Upper and lower polarizing plates each attached to an outer surface of the liquid crystal panel, and comprising a retardation film, a protective film laminated on both sides of the retardation film, and an adhesive laminated on one surface of the protective film and bonded to the liquid crystal panel; A backlight unit installed at a rear side of the liquid crystal panel to emit light over the entire surface of the liquid crystal panel; And a case part for fixing and coupling the liquid crystal panel and the backlight unit to each other, and controlling the shrinkage ratio of the upper and lower polarizers so that the liquid crystal panel becomes flat or otherwise weakly bent into a cup shape.

In this case, the backlight unit is characterized in that the LED package is arranged in the edge type on at least one side of the liquid crystal panel.

By controlling the elastic modulus of the retardation film, and the elastic modulus and adhesive force of the pressure-sensitive adhesive to control the shrinkage of the upper and lower polarizing plate is characterized in that the liquid crystal panel is flat or slightly bent cup shape.

The liquid crystal panel is characterized by having a degree of warpage of 0 to 3.5mm down under a 24-hour panel warpage test at 60 ° C.

The upper polarizer is composed of a retardation film of cycloolefin polymer (COP) having an elastic modulus of 6.67x10 ⁷ Pa and an adhesive for COP having an elastic modulus of 4.17x10 ⁵ Pa, while the lower polarizer is 2.3x10 ⁹ Pa It is characterized in that it is composed of an acrylic (acryl) retardation film having an elastic modulus and an adhesive for an acrylic retardation film having an elastic modulus of 3.58x10 ⁵ Pa.

The upper polarizer is composed of a COP retardation film having an elastic modulus of 6.67x10 ⁷ Pa and a pressure-sensitive adhesive for COP having an elastic modulus of 4.17x10 ⁵ Pa, while the lower polarizer is a retardation film of COP having an elastic modulus of 6.67x10 ⁷ Pa; It is characterized by consisting of a pressure-sensitive adhesive for COP having an elastic modulus of 4.48x10 ⁵ Pa.

The upper polarizer is composed of a low phase difference TAC film having an elastic modulus of 1.29x10 ⁸ Pa and an adhesive for a low phase difference TAC film having an elastic modulus of 1.27x10 ⁶ Pa, while the lower polarizer is formed of a COP having an elastic modulus of 6.67x10 ⁷ Pa. The retardation film and the pressure-sensitive adhesive for COP having an elastic modulus of 4.48x10 ⁵ Pa.

At this time, the pressure-sensitive adhesive for COP is characterized by consisting of an acrylate (acrylate) polymer, an isocyanate-based crosslinking agent, a silane coupling agent and an antistatic agent.

The COP film and the acrylic retardation film is characterized in that the film is formed by a melt extrusion (melt extrusion) method.

The low phase difference TAC film is characterized in that the film is put in the additive to lower the phase difference in the TAC film.

As described above, the liquid crystal display according to the present invention provides an effect of improving light leakage by reducing the amount of warpage of the liquid crystal panel by controlling the bending direction of the liquid crystal panel through designing the shrinkage ratio of the polarizing plate of the upper and lower substrates.

In addition, the liquid crystal display device according to the present invention provides an effect of securing the instrument interference margin due to the thinning of the liquid crystal display device (reducing the gap between the device and the liquid crystal panel).

1 is an exploded perspective view schematically illustrating a structure of a general liquid crystal panel.
2 is a cross-sectional view schematically showing a general liquid crystal display device.
3 is a cross-sectional view schematically illustrating a liquid crystal display device according to an exemplary embodiment of the present invention.
4 is a table showing the physical properties of the retardation film used in the liquid crystal display according to the embodiment of the present invention.
5 is a table showing the physical properties of the pressure-sensitive adhesive used in the liquid crystal display device according to an embodiment of the present invention.
FIG. 6 is a table illustrating a configuration of a polarizing plate for a liquid crystal display according to an exemplary embodiment of the present invention and a shrinkage ratio according thereto. FIG.
7A to 7E are 3D images schematically showing the amount of warpage for each combination of upper and lower polarizing plates in the polarizing plate for a liquid crystal display according to the exemplary embodiment of the present invention.
8A to 8E are photographs schematically showing light leakage of liquid crystal panels for combinations of upper and lower polarizing plates in a polarizing plate for a liquid crystal display according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of a liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view schematically illustrating a liquid crystal display device according to an exemplary embodiment of the present invention, and schematically illustrates a cross-sectional structure of one side of the liquid crystal display device.

As shown in the figure, the liquid crystal display according to the embodiment of the present invention is a liquid crystal panel that is largely formed between the color filter substrate 105 and the array substrate 110 to output an image, the rear of the liquid crystal panel And a guide panel 124 and an upper case 121 and a lower cover 122 which are installed in the backlight unit 140 to emit light over the entire surface of the liquid crystal panel, and fix and couple the liquid crystal panel and the backlight unit 140 to each other. ) And case parts.

At this time, the backlight unit 140 is configured of an edge type (edge type) in which the LED package is disposed on at least one side of the liquid crystal panel, the LED package for driving the LED array 145 and the LED for generating light The LED printed circuit board 144 and the LED array 145 are surrounded by an LED housing (not shown) that reflects light toward the light guide plate 142.

As described above, the light guide plate 142 is provided in the light exit direction of the LED array 145, and the light guide plate 142 of the LED array 145 is minimized in order to minimize the light that is not incident to the light guide plate 142. The LED housing can be introduced between and. At this time, the LED housing can improve the light receiving efficiency by attaching a reflector to the surface or by increasing the reflectance through a treatment such as a silver reflective coating.

The lamp housing 123 fixes the LED array 145 and the LED printed circuit board 144, wherein the lamp housing 123 has a reflector 143 disposed on the rear surface of the light guide plate 142. In order to prevent sagging, the reflective plate support part 123a may be provided.

The light generated by the LED array 145 is incident to the side of the light guide plate 142 of a transparent material, and the reflecting plate 143 disposed on the rear surface of the light guide plate 142 is transmitted to the rear surface of the light guide plate 142. The light is reflected toward the optical sheets 141 on the upper surface of the light guide plate 142 to reduce light loss and improve uniformity.

The liquid crystal panel including the color filter substrate 105 and the array substrate 110 is seated on the upper portion of the backlight unit 140 configured as described above, and is coupled to each other through the adhesive tapes 115a and 115b and the upper case 121. The display device is configured.

In this case, upper and lower polarizers 101 and 111 are attached to the outer surfaces of the color filter substrate 105 and the array substrate 110, respectively, and the upper polarizer 101 polarizes light passing through the liquid crystal panel. The lower polarizer 111 polarizes light via the optical sheets 141.

On the other hand, although not shown in detail in the drawing, the color filter substrate 105 distinguishes between the sub-color filter and the color filter composed of a plurality of sub-color filters for implementing the colors of red, green, and blue and transmits the liquid crystal layer. It consists of a black matrix to block light, and a transparent common electrode to apply a voltage to the liquid crystal layer. In the case of the transverse electric field type liquid crystal display, the common electrode is formed on an array substrate on which pixel electrodes are formed.

The array substrate 110 includes a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, a thin film transistor which is a switching element formed at an intersection of the gate lines and the data lines, and a pixel electrode formed on the pixel regions. Consists of In this case, the gate line and the data line are electrically connected to a gate printed circuit board (PCB) and a data printed circuit board through a tape tape carrier package (TCP) and a data tape carrier package, respectively. .

In addition, the upper and lower polarizing plates 101 and 111 include a retardation film having a thickness of about 30 μm, and a protective film having a thickness of about 80 μm represented by a triacetyl cellulose film (TAC) on both sides of the retardation film. Each of the protective film may be laminated through an adhesive, and one side of the protective film may have a multilayer structure in which an adhesive to be bonded to the liquid crystal panel is laminated.

Since the constituent films of the upper and lower polarizing plates 101 and 111 are made of materials having different molecular structures and compositions, they have different physical and chemical properties. For example, a retardation film, a film in which a polyvinyl alcohol (PVA) resin is stretched, shrinks or expands under high temperature and humidity, and a TAC film as a support prevents this phenomenon. However, at high temperatures, the supportability of the TAC is weakened due to the characteristics of the polymer material, and the deformation of the TAC and PVA occurs to some extent by the contraction force of the PVA. Accordingly, durability of the constituent films of the upper and lower polarizing plates 101 and 111 may be bent or easily dropped, bubbles may be deteriorated, and the deformed TAC film may have refractive index anisotropy, thereby refracting incident light at various angles. Light leakage occurs.

In addition, the liquid crystal display device according to the embodiment of the present invention configured as described above has an adhesive tape 115a attached between the upper case 121 and the liquid crystal panel, specifically, the upper case 121 to reduce the thickness of the liquid crystal display device. The gap between the upper polarizers 101 on the upper side of the liquid crystal panel is reduced from about 1 mm to about 0.5 mm.

As the gap between the liquid crystal panel and the mechanism gradually decreases and the size of the liquid crystal display device increases, the amount of warpage of the liquid crystal panel becomes relatively large and light leakage occurs due to deformation of the liquid crystal array due to the pressing of the liquid crystal panel.

Accordingly, the present invention is characterized by improving the light leakage according to the size and thickness of the liquid crystal display device by controlling the bending direction of the liquid crystal panel through the shrinkage ratio design of the upper and lower polarizing plates (101, 111). That is, by designing the elastic modulus of the retardation film, the elastic modulus of the pressure-sensitive adhesive and the adhesive force, the light leakage can be improved by designing the long and short side shrinkages of the upper and lower polarizing plates 101 and 111 to predict and control the bending direction of the liquid crystal panel. .

For reference, even if the shrinkage ratios of the upper and lower polarizers 101 and 111 are designed to be the same, the liquid crystal panel is substantially curved up or down. As the size of the LCD increases, the degree of warpage of the liquid crystal panel increases.

At this time, when the liquid crystal panel is bent upward, as described above, the gap between the liquid crystal panel and the mechanism gradually decreases, so that the pressing occurs at the edge of the liquid crystal panel by a mechanism such as the upper case 121. At this time, although it depends on the size and configuration of the liquid crystal display device, the degree of warpage that is allowed to prevent light leakage due to the pressing of the liquid crystal panel is about 0 ~ 1mm. For reference, as an example, the degree of warpage refers to a difference in height between the liquid crystal panels generated as a result of panel warpage tests at 60 ° C. for 24 hours.

On the other hand, when the liquid crystal panel is bent downward, the liquid crystal panel is less likely to be pressed by the mechanism as compared to the above-mentioned case, but when the lower polarizing plate 111 contacts the lower optical sheet 141, the egg mura (egg mura) may occur, and depending on the size and configuration of the liquid crystal display device, the allowable deflection is about 0 to 3.5 mm.

From the above results, it can be seen that the liquid crystal panel is flat in the light leakage side, or the cup shape bent slightly downwardly is advantageous. For this purpose, in the present invention, the shrinkage control of the upper and lower polarizers 101 and 111 is performed. When the polarizers 101 and 111 are attached, the bending direction of the liquid crystal panel is designed to have a cup shape. In addition, it is characterized by reducing the shrinkage compared to the existing by increasing the drying and less stretching for the conventional retardation film.

4 is a table showing the physical properties of the retardation film used in the liquid crystal display according to the embodiment of the present invention.

Referring to FIG. 4, in the retardation film, the modulus of elasticity is a main factor influencing the shrinkage of the polarizing plate, and Pascal (Pa) is an SI induction unit with respect to pressure. Corresponds to pressure.

At this time, the retardation film A is a cycloolefin polymer (COP) film having an elastic modulus of 5.0x10 ⁷ Pa to 8.0x10 ⁷ Pa, preferably about 6.67x10 ⁷ Pa, and the retardation film B is 1.0x10 ⁸ Pa to 3.0 x10 ⁸ Pa, preferably in the low retardation TAC film with an elastic modulus of approximately 1.29x10 ⁸ Pa, the retardation film C is 1.0x10 ⁹ Pa ~ 4.0x10 ⁹ Pa, preferably from acrylic with a modulus of elasticity of about 2.3x10 ⁹ Pa ( acryl) system retardation film.

The coefficient of thermal expansion (CTE) of the retardation film A, the retardation film B, and the retardation film C is about 99 ppm / K, 60 ppm / K, and 60 ppm / K, respectively.

For reference, the COP film and the acrylic retardation film may be formed by a melt extrusion method. The melt extrusion method is the same as the extrusion method, but a binder that may be melted at a high temperature without using water is used. It is kneaded at high temperature and then extruded through a screen. In addition, the low phase difference TAC film can be formed by putting an additive that lowers the phase difference in the TAC film.

5 is a table showing the physical properties of the pressure-sensitive adhesive used in the liquid crystal display device according to an embodiment of the present invention.

Referring to FIG. 5, the elastic modulus and the adhesive force of the pressure-sensitive adhesive are factors influencing the shrinkage of the polarizer, and 1 gf (gram force) corresponds to about 0.00980665N.

In this case, a pressure-sensitive adhesive is 4.1x10 ⁵ Pa ~ 4.2x10 ⁵ Pa, preferably in the COP for the pressure-sensitive adhesive having a modulus of elasticity of about 4.17x10 ⁵ Pa, the pressure-sensitive adhesive b is 4.4x10 ⁵ Pa ~ 4.5x10 ⁵ Pa, preferably from about 4.48 COP pressure-sensitive adhesive having an elastic modulus of x10 ⁵ Pa, and the pressure-sensitive adhesive for COP is basically composed of an acrylate polymer, an isocyanate crosslinker, a silane coupling agent, and an antistatic agent. .

In addition, the pressure-sensitive adhesive c is a pressure-sensitive adhesive for low phase difference TAC film having an elastic modulus of 1.0x10 ⁶ Pa to 2.0x10 ⁶ Pa, preferably about 1.27x10 ⁶ Pa, and the adhesive d is 3.0x10 ⁵ Pa to 4.0x10 ⁵ Pa, preferably Is an adhesive for acrylic retardation films having an elastic modulus of about 3.58x10 ⁵ Pa.

In addition, the adhesive strengths of the pressure-sensitive adhesive a, pressure-sensitive adhesive b, pressure-sensitive adhesive c and pressure-sensitive adhesive d are about 271 gf / mm, 242 gf / mm, 329 gf / mm and 1041 gf / mm, respectively.

FIG. 6 is a table illustrating a configuration of a polarizing plate for a liquid crystal display according to an exemplary embodiment of the present invention and a shrinkage rate thereof, and shows a result of a panel bending test performed at 80 ° C. for 24 hours.

Referring to FIG. 6, the polarizing plate I is composed of a phase difference film A and an adhesive b in a conventional structure, and shows shrinkage ratios of −0.151 and −0.165 in the upper and lower polarizing plates, respectively.

The polarizing plate II is composed of a retardation film A and an adhesive a, the polarizing plate III is composed of a retardation film B and an adhesive c, and the polarizing plate IV is composed of a retardation film C and an adhesive d.

In this case, in the case of the polarizing plate II, the shrinkage ratios are -0.221 and -0.227 in the upper and lower polarizing plates, respectively, and in the case of the polarizing plate III, the shrinkage in the upper and lower polarizing plates is -0.105 and -0.086, respectively. In the case of the polarizing plate IV, the shrinkage ratio of the lower polarizing plate is -0.120.

When the upper and lower polarizers of the liquid crystal display were designed using the combination of the above configurations, the panel bending test for 24 hours showed the best results when the combination of the polarizers II and IV were used as the upper and lower polarizers. . However, in consideration of the convenience of the process, good results can be obtained when the combination of the polarizing plates II and I or the combination of the polarizing plates III and I is used as the upper and lower polarizing plates.

7A to 7E are 3D images schematically illustrating the amount of warpage for each combination of the upper and lower polarizing plates in the polarizing plate for the liquid crystal display according to the exemplary embodiment of the present invention.

8A to 8E are photographs schematically showing light leakage of liquid crystal panels for combinations of upper and lower polarizing plates in the polarizing plate for the liquid crystal display according to the exemplary embodiment of the present invention.

7A and 8A schematically show the amount of warpage and the light leakage of the liquid crystal panel when the combination of the polarizing plates I and I is used as the upper and lower polarizers, and the light leakage is large in the state where the liquid crystal panel is bent upward. It can be seen that this occurs strongly.

7b and 8b schematically show the amount of warpage and the light leakage of the liquid crystal panel when the combination of the polarizers III and II is used as the upper and lower polarizers, and the height difference is relatively large in the state where the liquid crystal panel is bent upward. It can be seen that this occurred.

7C and 8C schematically show the amount of warpage and the light leakage of the liquid crystal panel when the combination of the polarizing plates III and I is used as the upper and lower polarizing plates, and the light leakage is improved due to the relatively small height difference in the state where the liquid crystal panel is bent upward. It can be seen that.

7D and 8D schematically show the amount of warpage and the light leakage of the liquid crystal panel when the combination of the polarizers II and IV are used as the upper and lower polarizers, and the light leakage is improved because the height difference is relatively small when the liquid crystal panel is bent downward. You can see that.

7E and 8E schematically show the amount of warpage and the light leakage of the liquid crystal panel when the combination of the polarizing plates II and I is used as the upper and lower polarizers, and the light leakage is relatively small in the state where the liquid crystal panel is bent downward. It can be seen that this improvement.

As such, when the shrinkage ratio of the upper and lower polarizers is controlled to design a cup shape in which the bending direction of the liquid crystal panel is weakly bent downward when the polarizer is attached, light leakage due to the enlargement and thickness of the liquid crystal display device can be improved.

In addition, while drying the PVA drying drying by increasing the drying temperature, it is possible to reduce the shrinkage compared to the existing by reducing the stretching.

Many details are set forth in the foregoing description but should be construed as illustrative of preferred embodiments rather than to limit the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

101,111 polarizer 105 color filter substrate
110: array substrate 115a, 115b: adhesive tape
121: upper case 122: lower cover
140: backlight unit 141: optical sheet
142: light guide plate 143: reflector
144: LED printed circuit board 145: LED array

Claims (13)

A liquid crystal panel formed between the color filter substrate and the array substrate to output an image;
Upper and lower polarizing plates each attached to an outer surface of the liquid crystal panel, and comprising a retardation film, a protective film laminated on both sides of the retardation film, and an adhesive laminated on one surface of the protective film and bonded to the liquid crystal panel;
A backlight unit installed at a rear side of the liquid crystal panel to emit light over the entire surface of the liquid crystal panel; And
And a case component for fixing and coupling the liquid crystal panel and the backlight unit to each other, and controlling the shrinkage ratio of the upper and lower polarizers so that the liquid crystal panel becomes flat or otherwise weakly bent into a cup shape. Device. The liquid crystal display device according to claim 1, wherein the backlight unit has an edge type in which an LED package is disposed on at least one side of the liquid crystal panel. The liquid crystal panel of claim 1, wherein the contraction rate of the upper and lower polarizers is controlled by designing the elastic modulus of the retardation film, the elastic modulus of the pressure sensitive adhesive, and the adhesive force to make the liquid crystal panel flat or otherwise bend slightly downward. A liquid crystal display device. The liquid crystal display device according to claim 1, wherein the liquid crystal panel has a degree of warpage of 0 to 3.5 mm under a 24 hour panel warpage test at 60 ° C. The method of claim 1, wherein the upper polarizing plate is a retardation film of cycloolefin polymer (COP) having an elastic modulus of 5.0x10 ⁷ Pa ~ 8.0x10 ⁷ Pa and a COP having an elastic modulus of 4.1x10 ⁵ Pa ~ 4.2x10 ⁵ Pa The lower polarizing plate is composed of an acryl-based retardation film having an elastic modulus of 1.0x10 ⁹ Pa to 4.0x10 ⁹ Pa, and an acryl-based retardation film having an elastic modulus of 3.0x10 ⁵ Pa to 4.0x10 ⁵ Pa. Liquid crystal display device characterized in that consisting of. The method of claim 5, wherein the upper polarizing plate is composed of a phase difference film of COP having an elastic modulus of 6.67x10 ⁷ Pa and an adhesive for COP having an elastic modulus of 4.17x10 ⁵ Pa, while the lower polarizing plate has an elastic modulus of 2.3x10 ⁹ Pa. And an acryl-based retardation film and a pressure-sensitive adhesive for an acryl-based retardation film having an elastic modulus of 3.58x10 ⁵ Pa. The method of claim 1, wherein the upper polarizing plate is composed of a phase difference film of COP having an elastic modulus of 5.0x10 ⁷ Pa to 8.0x10 ⁷ Pa and an adhesive for COP having an elastic modulus of 4.1x10 ⁵ Pa to 4.2x10 ⁵ Pa, the lower polarizing plate is a liquid crystal display device, characterized in that for the pressure-sensitive adhesive consisting of COP with a modulus of elasticity of 5.0x10 ⁷ Pa ~ 8.0x10 ⁷ Pa of COP retardation film and 4.4x10 ⁵ Pa ~ 4.5x10 ⁵ Pa with a modulus of elasticity of. 8. The method of claim 7, wherein the upper polarizer is composed of a phase difference film of COP having an elastic modulus of 6.67x10 ⁷ Pa and the pressure-sensitive adhesive for COP having an elastic modulus of 4.17x10 ⁵ Pa, while the lower polarizing plate has an elastic modulus of 6.67x10 ⁷ Pa. Liquid crystal display device comprising a phase difference film of the COP having a pressure-sensitive adhesive for COP having an elastic modulus of 4.48x10 ⁵ Pa. According to claim 1, wherein the upper polarizing plate is composed of a low phase difference TAC film having an elastic modulus of 1.0x10 ⁸ Pa ~ 3.0x10 ⁸ Pa and an adhesive for low phase difference TAC film having an elastic modulus of 1.0x10 ⁶ Pa ~ 2.0x10 ⁶ Pa. on the other hand, the lower polarizing plate is a liquid crystal display device, characterized in that for the pressure-sensitive adhesive consisting of COP with a modulus of elasticity of 5.0x10 ⁷ Pa ~ 8.0x10 ⁷ Pa of COP retardation film and 4.4x10 ⁵ Pa ~ 4.5x10 ⁵ Pa with a modulus of elasticity of the . 10. The method of claim 9, wherein the upper polarizing plate is composed of a low phase difference TAC film having a modulus of elasticity of 1.29x10 ⁸ Pa and an adhesive for a low phase difference TAC film having a modulus of elasticity of 1.27x10 ⁶ Pa, while the lower polarizing plate is 6.67x10 ⁷ Pa Liquid crystal display device comprising a retardation film of COP having a modulus of elasticity and a pressure-sensitive adhesive for COP having a modulus of elasticity of 4.48x10 ⁵ Pa. The pressure sensitive adhesive for COP according to any one of claims 5 to 10, comprising an acrylate polymer, an isocyanate crosslinking agent, a silane coupling agent and an antistatic agent. A liquid crystal display device. The liquid crystal display device according to any one of claims 5 to 10, wherein the COP film and the acrylic retardation film are formed by a melt extrusion method. 20. The liquid crystal display device according to any one of claims 9 and 19, wherein the low phase difference TAC film is formed by adding an additive for lowering the phase difference to the TAC film.

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