KR20100000793A - In plane switching mode liquid crystal display device having optical compensation film - Google Patents

Abstract

In the transverse electric field type liquid crystal display device including the optical compensation film of the present invention, a biaxial phase difference film and a positive C plate ((+) C plate) are applied to the top, bottom, left, and right sides in a dark state. A liquid crystal display panel comprising: a color filter substrate including an color filter, an array substrate, and a liquid crystal layer formed between the color filter substrate and the array substrate to improve contrast ratio in the direction and to improve image quality; A first polarizing plate disposed under the liquid crystal display panel and including a first polarizing element and a first optical compensation film positioned between the first polarizing element and the liquid crystal display panel; And a second polarizing plate disposed on an upper portion of the liquid crystal display panel, the second polarizing plate including a second polarizing element and a support positioned between the second polarizing element and the liquid crystal display panel, wherein the first optical compensation film is 0.1 ≦ Nz ≦. 0.5, where Nz = Rth / Re, Re = (nx-ny) · d and Rth = (nx-nz) · d, where nx, ny and nz are respectively defined in the x, y and z directions. It refers to the refractive index of, d means the thickness of the film) is made of a biaxial compensation film, characterized in that the second optical compensation film made of a positive C plate between the liquid crystal layer and the second polarizing plate.

In this case, the transverse electric field type liquid crystal display device including the optical compensation film of the present invention can simplify the structure of the polarizing plate by using the positive C plate instead of an overcoat layer that reduces the step of the color filter. It features.

Description

Transverse electric field liquid crystal display device including optical compensation film {IN PLANE SWITCHING MODE LIQUID CRYSTAL DISPLAY DEVICE HAVING OPTICAL COMPENSATION FILM}

The present invention relates to a transverse electric field type liquid crystal display device, and more particularly, to a transverse electric field type liquid crystal display device including an optical compensation film for improving contrast ratios in up, down, left, and right directions.

Recently, with increasing interest in information display and increasing demand for using a portable information carrier, a lightweight flat panel display (FPD), which replaces a conventional display device, a cathode ray tube (CRT), is used. The research and commercialization of Korea is focused on. In particular, the liquid crystal display (LCD) of the flat panel display device is an image representing the image using the optical anisotropy of the liquid crystal, is excellent in resolution, color display and image quality, and is actively applied to notebooks or desktop monitors have.

The liquid crystal display is largely composed of a color filter substrate as a first substrate, an array substrate as a second substrate, and a liquid crystal layer formed between the color filter substrate and the array substrate.

In this case, the color filter substrate is formed between a color filter composed of a plurality of sub-color filters that implements red (R), green (G), and blue (B) colors and the sub-color filter. A black matrix for dividing and blocking light passing through the liquid crystal layer, and a transparent common electrode for applying a voltage to the liquid crystal layer.

The array substrate may include a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, thin film transistors (TFTs), which are switching elements formed at intersections of the gate lines and data lines, and the The pixel electrode is formed on the pixel region.

The color filter substrate and the array substrate configured as described above are joined to face each other by sealants formed on the outer side of the image display area to form a liquid crystal display panel. The color filter substrate and the array substrate are bonded to each other by the color filter substrate or the substrate. It is made through a bonding key formed on the array substrate.

In this case, the above-described liquid crystal display device represents a twisted nematic (TN) type liquid crystal display device which drives the nematic liquid crystal molecules in a direction perpendicular to the substrate, and the liquid crystal display device of the type has a viewing angle of 90 degrees. It has the disadvantage of being too narrow. This is due to the refractive anisotropy of the liquid crystal molecules because the liquid crystal molecules oriented horizontally with the substrate are oriented almost perpendicular to the substrate when a voltage is applied to the liquid crystal display panel.

Accordingly, there is an in-plane switching (IPS) type liquid crystal display device in which a liquid crystal molecule is driven in a horizontal direction with respect to a substrate to improve the viewing angle to 170 degrees or more. Hereinafter, the transverse field type liquid crystal display device will be described with reference to the accompanying drawings. It will be described in detail.

1 is a plan view schematically illustrating a portion of an array substrate of a general transverse electric field type liquid crystal display device. In an actual liquid crystal display device, N gate lines and M data lines intersect to present MxN pixels, but the description will be simplified. For the sake of illustration, one pixel is shown.

FIG. 2 is an exemplary view illustrating a cross section taken along line II ′ of the array substrate illustrated in FIG. 1, and illustrates the array substrate illustrated in FIG. 1 and the color filter substrate bonded together corresponding to the array substrate. .

1 and 2, a gate line 16 and a data line 17 are formed on the transparent array substrate 10 to be arranged on the array substrate 10 vertically and horizontally to define a pixel area. The thin film transistor T, which is a switching element, is formed at the intersection of the gate line 16 and the data line 17.

In this case, the thin film transistor T may include a pixel electrode 18 through a gate electrode 21 connected to the gate line 16, a source electrode 22 connected to the data line 17, and a pixel electrode line 18l. It is composed of a drain electrode 23 connected to. In addition, the thin film transistor may be formed by the first insulating layer 15a for insulation between the gate electrode 21 and the source / drain electrodes 22 and 23 and the source electrode by a gate voltage supplied to the gate electrode 21. And an active pattern 24 for forming a conductive channel between the 22 and the drain electrode 23.

For reference, reference numeral 25 denotes an ohmic contact layer for ohmic contact between the source / drain region of the active pattern 24 and the source / drain electrodes 22 and 23.

At this time, the common line 8l and the storage electrode 18s are arranged in a direction parallel to the gate line 16 in the pixel region, and a transverse electric field 90 is generated in the pixel region to generate liquid crystal molecules (not shown). A plurality of common electrodes 8 and pixel electrodes 18 for switching the light source) are arranged in a direction parallel to the data line 17.

In this case, the storage electrode 18s overlaps a portion of the common line 8l below the first insulating layer 15a to form a storage capacitor Cst.

In addition, the transparent color filter substrate 5 implements the black matrix 6 and red, green and blue colors that prevent light leakage from the thin film transistor T, the gate line 16 and the data line 17. The color filter 7 for this is formed.

At this time, although not shown in the drawing, the upper surface of the color filter 7 is planarized by removing a step that occurs as a part of the color filters 7 overlap with the black matrix 6 on the color filter 7. An overcoat layer is formed to play a role.

On the opposite surface of the array substrate 10 and the color filter substrate 5 configured as described above, an alignment film (not shown) for determining the initial alignment direction of the liquid crystal molecules is formed, and the array substrate ( 10) and a polarizing plate (not shown) are disposed on the outer surface of the color filter substrate 5 so that the light transmission axes are perpendicular to each other.

In the general transverse electric field type liquid crystal display device having the above structure, the common electrode 8 and the pixel electrode 18 are disposed on the same array substrate 10 to generate a transverse electric field, and the liquid crystal molecules are formed on the array substrate 10. Since it is arranged in parallel with the transverse electric field parallel to the has a merit that can improve the viewing angle.

However, such a transverse electric field type liquid crystal display has a problem in that light leakage occurs in a diagonal direction when displaying a black state, thereby showing a low contrast ratio.

FIG. 3A illustrates a simulation result of luminance viewing angle characteristics of a dark state in a general transverse electric field type liquid crystal display device, and FIG. 3B illustrates simulation results of contrast ratio characteristics of a dark state. Drawing.

3A and 3B illustrate luminance viewing angle characteristics and contrast ratio characteristics of a dark state when a triacetyl cellulose (TAC) film is applied between a PVA (polyvinyl acetate) layer and a liquid crystal layer of a polarizing plate. For example.

In addition, the lower polarizing plate and the upper polarizing plate are arranged such that the light absorption axes are perpendicular to each other, and the optical axis of the liquid crystal layer, that is, the rubbing direction of the liquid crystal layer is in an E-mode state perpendicular to the light absorption axis of the lower polarizing plate.

As shown in the drawing, in the dark state, large light leakage occurs at 45 degrees, 135 degrees, 225 degrees, and 315 degrees corresponding to the diagonal direction of the liquid crystal display panel, thereby increasing the brightness, and accordingly the contrast of the liquid crystal display device. It can be seen that the contrast ratio is lowered.

However, such a problem is not a problem of the transverse type liquid crystal display itself, but a problem due to a polarizing plate which is generally used. That is, in general, diagonal light leakage has a greater effect due to the polarizing plate than the effect due to the liquid crystal layer. Like the transverse electric field type liquid crystal display, the transverse electric field mode can determine the initial alignment state so as not to be affected by the liquid crystal in all directions. In this case, light leakage is entirely due to the polarizer.

This is because even if the light absorption axes of the polarizing plates are orthogonal to each other, as shown in FIGS. 4A and 4B, the orthogonality of the two polarizing plates is broken along the viewing angle direction. At this time, the solid lines shown in FIGS. 4A and 4B represent, for example, the light absorption axis direction of the upper polarizing plate, and the dotted line represents the light absorption axis direction of the lower polarizing plate.

As shown in FIG. 4A, when the LCD panel is viewed from the front, the light absorption axes of the upper and lower polarizers form 90 degrees to realize a dark state. However, as shown in FIG. 4B, the LCD displays in a diagonal direction. When looking at the panel, light leakage occurs because the light absorption axis of the upper and lower polarizers is 90 degrees or more, and the orthogonality of the two polarizers is broken.

As described above, the transverse electric field type liquid crystal display device is a method in which a transverse electric field is applied to the liquid crystal layer, so that the change in phase retardation of the liquid crystal is small according to voltage and the optical axis of the upper and lower polarizers is vertical in the up, down, left, and right directions. Although excellent in the optical axis of the upper and lower polarizers, light leakage occurs in a diagonal direction in which the vertical state is broken, causing deterioration of image quality.

In order to improve such deterioration of image quality in a diagonal direction, a compensation film should be applied, but compensation is limited in current optical compensation films that protect the PVA layer of the polarizer. At this time, the PVA layer is a polarizing element that determines the polarization characteristics of the polarizing plate, so it is generally vulnerable to moisture, so it is generally protected using a film such as TAC or 0-RT TAC (Tth close to 0 nm). This is because the cracking of the vertical conditions of the upper and lower polarizers in the direction cannot be compensated for.

An object of the present invention is to provide a transverse electric field type liquid crystal display device including an optical compensation film to prevent light leakage in a diagonal direction in a dark state.

Another object of the present invention is to provide a transverse electric field type liquid crystal display device including an optical compensation film that simplifies the structure of a polarizing plate.

Other objects and features of the present invention will be described in the configuration and claims of the invention described below.

In order to achieve the above object, a transverse electric field type liquid crystal display device including the optical compensation film of the present invention comprises a color filter substrate and an array substrate including a color filter and a liquid crystal layer formed between the color filter substrate and the array substrate A liquid crystal display panel; A first polarizing plate disposed under the liquid crystal display panel and including a first polarizing element and a first optical compensation film positioned between the first polarizing element and the liquid crystal display panel; And a second polarizing plate disposed on an upper portion of the liquid crystal display panel, the second polarizing plate including a second polarizing element and a support positioned between the second polarizing element and the liquid crystal display panel, wherein the first optical compensation film is 0.1 ≦ Nz ≦. 0.5, where Nz = Rth / Re, Re = (nx-ny) · d and Rth = (nx-nz) · d, where nx, ny and nz are respectively defined in the x, y and z directions. It refers to the refractive index of, d means the thickness of the film), characterized in that the second optical compensation film made of a biaxial compensation film made of a positive C plate between the liquid crystal layer and the second polarizing plate.

As described above, the transverse electric field type liquid crystal display device including the optical compensation film according to the present invention provides an effect of improving contrast ratio of a diagonal viewing angle by reducing light leakage in a diagonal direction in a dark state.

In addition, the transverse electric field liquid crystal display including the optical compensation film according to the present invention provides an effect of reducing the cost by simplifying the structure of the polarizing plate by using the positive C plate instead of the overcoat layer to reduce the step of the color filter. .

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of a transverse electric field type liquid crystal display device including an optical compensation film according to the present invention.

5 is a cross-sectional view schematically illustrating a transverse electric field type liquid crystal display device including an optical compensation film according to a first embodiment of the present invention.

As shown in the drawing, the transverse electric field type liquid crystal display device 100 according to the first exemplary embodiment of the present invention includes a liquid crystal display panel 110 for outputting an image and a lower portion of the liquid crystal display panel 110. The first polarizer 105 and the second polarizer 115 are disposed on the liquid crystal display panel 110. Here, the upper and lower portions of the liquid crystal display panel 110 do not limit a specific position. Therefore, the first polarizing plate 105 is positioned on the upper portion of the liquid crystal display panel 110 and the lower portion of the liquid crystal display panel 110. The second polarizer 115 may be located at.

In this case, the liquid crystal display panel 110 includes a color filter substrate 101 and an array substrate 111, and a liquid crystal layer 140 formed between the color filter substrate 101 and the array substrate 111.

In this case, the liquid crystal layer 140 may include a nematic liquid crystal homogeneously oriented in the absence of an electric field, and the liquid crystal layer may exhibit a refractive index distribution of nx> ny = nz. , The in-plane refractive index is nx and ny, and the refractive index in the thickness direction is nz). At this time, in this specification, ny = nz includes not only the case where ny and nz are completely the same, but also the case where ny and nz are substantially the same.

As a drive mode which uses the liquid crystal layer which shows such refractive index distribution, a transverse electric field system, a fringe field switching (FFS) mode, etc. are mentioned, for example.

The transverse electric field method uses a voltage controlled birefringence (ECB) effect to drive a homogeneously oriented nematic liquid crystal in the absence of an electric field through a transverse electric field formed of a pixel electrode and a common electrode. to be.

In addition, the FFS mode is driven in the same manner as the transverse electric field method. The lateral electric field of the FFS mode is called a fringe field, and the fringe field has a gap between the upper and lower substrates between the pixel electrode and the common electrode formed of a transparent conductive material. It can form by setting narrower than the space | interval.

In the case of the first embodiment of the present invention, a transverse electric field type liquid crystal display device is described as an example, but the present invention is not limited thereto, and the present invention may be applied to the FFS mode liquid crystal display device.

The color filter substrate 101 includes a color filter 107 composed of a plurality of sub-color filters for implementing colors of red (R), green (G), and blue (B), and the sub- It is composed of a black matrix (not shown) that separates the color filters and blocks the light passing through the liquid crystal layer 140.

In addition, although not shown in the drawing, the array substrate 111 is a thin film transistor that is a switching element formed in a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, and intersecting regions of the gate lines and data lines. And a pixel electrode and a common electrode formed on the pixel region to generate a transverse electric field.

The first polarizer 105 includes a first polarizer 103 and a first optical compensation film 120 positioned between the first polarizer 103 and the liquid crystal display panel 110. The second polarizer 115 includes a second polarizer 113 and a support 112 positioned between the second polarizer 113 and the liquid crystal display panel 110.

In this case, the first polarizing element 103 and the second polarizing element 113 may be made of polyvinyl alcohol (PVA), and the support 112 may be phase retarded to protect the PVA layer. ) Can be made of a general protection film (protection film), and in the case of the first embodiment can be made of 0-RT TAC.

In addition, the first polarizing device 103 and the second polarizing device 113 refers to a film that can be converted from natural light or polarized light into any polarized light. At this time, when the incident light is divided into two orthogonal polarization components, the first polarization element 103 and the second polarization element 113 have a function of allowing one polarization component to pass therethrough, and the other polarization component. One having at least one function selected from the functions of absorbing, reflecting and scattering components can be used.

The optical film used for the first polarizing element 103 and the second polarizing element 113 is not particularly limited, but is, for example, a polymer film containing, as a main component, a PVA-based resin containing iodine or a dichroic dye. The O type polarizing element which orientated the oriented film, the liquid crystalline composition containing a dichroic substance, and a liquid crystalline compound to a fixed direction, and the E type polarizing element which orientated a lyotropic liquid crystal to a fixed direction, etc. are mentioned.

The first polarization element 103 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarization element 113 facing each other, that is, the optical axis of the liquid crystal layer 140, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizing element 103.

In addition, the second optical compensation film 130 of the present invention is formed on the color filter substrate 101 instead of the overcoat layer for reducing the step of the color filter 107. In this case, the first embodiment of the present invention The second optical compensation film 130 is positioned between the color filter 107 and the liquid crystal layer 140 of the color filter substrate 101.

In the case of the first embodiment of the present invention, the first optical compensation film 120 and the second optical are respectively formed in the first polarizing plate 105 and the liquid crystal display panel 110 in order to improve the viewing angle characteristic in the diagonal direction. Compensation film 130 is disposed, wherein the first optical compensation film 120 is formed of a biaxial TAC of 0.1≤Nz≤0.5 while the second optical compensation film 130 is 10≤Rth It is characterized by forming a positive C plate ((+) C plate) of ≤ 100nm.

At this time, the definition of Re and Rth and Nz used in the present invention is as shown in Equation 1 below.

Re = (nx-ny) d

Rth = (nx-nz)

Nz = Rth / Re

In this case, nx, ny, and nz denote refractive indexes in the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively, and d represents the thickness of the film. That is, when the in-plane refractive index is maximized in the X axis, the direction perpendicular to the X axis is in the Y axis, and the film thickness direction is in the Z axis, the refractive indices at 550 nm in the respective axial directions are nx, ny, and nz. Represented by

Accordingly, Re denotes an in-plane phase delay value, and Rth denotes a phase delay value in the thickness direction. In addition, Nz represents the biaxiality degree of a biaxial retardation film.

The biaxial TAC according to the first embodiment of the present invention is an optical compensation film having 0.1≤Nz≤0.5, and the in-plane retardation Re may have a value of 100≤Re≤150nm, and the positive C plate has a phase difference Rth in the thickness direction. May have a value of 0 ≦ Rth ≦ 100 nm.

Here, the phase delay values of all the films applied to the present invention may have an error of about 10 nm substantially due to a process variation or an external influence.

The first optical compensation film 120 and the second optical compensation film 130 according to the first embodiment of the present invention having such optical conditions are formed in the diagonal direction of the first and second polarizing plates 105 and 115. By compensating for breaking of orthogonality, it is possible to reduce light leakage in the diagonal direction, which will be described in detail using a Poincare sphere representation.

In order to geometrically interpret the optical properties of transparent media such as liquid crystals, we use the Poangkar sphere representation of the polarization state.

First, the Jones vector may represent only fully polarized light, and a Stokes parameter defined as in Equation 2 below is used to express a more general partial polarized light.

는 시간평균을 나타내며, 이 네 변수 사이에는

의 부등식이 성립하는데, 등식은 완전편광에서만 적용된다.At this time,

Represents the time average, and between these four variables

The inequality of holds, which applies only to complete polarization.

In the case of fully polarized light, the relationship of Equation 3 is established between the standardized variables s ₁ , s _2, and s ₃ obtained by dividing S ₁ , S _2, and S ₃ by the brightness S ₀ of light.

This is the equation of a sphere of radius 1 in three-dimensional space, where a sphere composed of points with (s ₁ , s ₂ , s ₃ ) as Cartesian coordinates is a Poangare sphere.

In this case, all the points on the equator line in the Poangkar sphere correspond to linear polarization, the polar point corresponds to the right hand circular polarization, and the south pole corresponds to the left hand circular polarization. And all the points in the northern hemisphere correspond to the right hand ellipse polarization, and all the points in the southern hemisphere correspond to the left hand ellipse polarization.

6A and 6B are diagrams illustrating an arbitrary elliptical polarization and a corresponding poang curry vector in a rectangular coordinate system.

이다. 이 점이 북반구에 있으면 전기장 벡터의 회전방향이 시계방향이고 남반구에 있으면 반시계방향이다. 뽀앙카레 구 위의 대척점들은 서로 직교하는 편광 상태를 나타낸다.As shown in the figure, the latitude angle of the Poangcurry vector P corresponding to the elliptically polarized light having an azimuthal angle Ψ and an ellipse angle x of the long axis of the polarized ellipse is 2x, the azimuth is 2Ψ, and the Cartesian coordinate Is

to be. If this point is in the northern hemisphere, the direction of rotation of the electric field vector is clockwise; in the southern hemisphere, it is counterclockwise. The opposite points on the Poangcurry sphere represent polarization states orthogonal to each other.

In addition, the Unitary Jones matrix, which describes the change in polarization state when light passes through a transparent medium, can be interpreted as a rotational transformation on a Poangcurry sphere.

FIG. 7 is a view showing a Poangcurry sphere showing a polarization state of light passing through each optical element in the transverse electric field type liquid crystal display device according to the first embodiment of the present invention having the structure of FIG. In the case of diagonal view, Poangcurry district is shown.

At this time, although the arrows indicate the movement before and after each change in the polarization state, the change in the polarization state of the light passing through each optical element is changed to a specific angle around a specific axis determined according to each optical characteristic. It can be represented on a Poangcurry sphere by rotation.

As shown in the figure, all of the points on the equator line in this Poangkar sphere represent linear polarization, the point at the North Pole S ₃ represents the right hand circular polarization, and the point at the South Pole -S ₃ represents the left hand circular polarization. In addition, the northern hemisphere of the remaining regions exhibits right-hand elliptical polarization and the southern hemisphere exhibits left-hand elliptical polarization.

At this time, when the liquid crystal display is viewed from the front, the polarization states of the upper polarizer and the lower polarizer are symmetrical with respect to the center O of the Poangcurry sphere, so that they are perpendicular to each other to display an excellent dark state.

However, when the liquid crystal display is viewed from a diagonal direction, the absorption axis A and the transmission axis (-A) of the upper polarizer and the transmission axis P and the absorption axis (-P) of the lower polarizer are shifted by a predetermined distance. As a result, polarization states of the upper polarizer and the lower polarizer are not symmetrical with respect to the center O of the Poangcurry sphere, and thus polarization states of the upper and lower polarizers are not perpendicular to each other. Therefore, the optical axis of the light reaching the upper polarizer using the optical compensation film according to the first embodiment of the present invention should be made to coincide with the absorption axis (A) of the upper polarizer. That is, in order to prevent light leakage in the diagonal direction, the polarization of the P position should be moved to the A position.

Referring to FIG. 7, the polarization state of incident light passing through the lower polarizer corresponds to point P, and the polarization state of light absorbed and blocked by the absorption axis of the upper polarizer corresponds to point A. .

As described above, in the transverse electric field type liquid crystal display device, light leakage off the axis in the diagonal direction is caused by a mismatch between the points P and A. Therefore, the optical compensation film according to the first embodiment of the present invention is used to cause a change in the polarization state of incident light from point P to point A, including a change in the polarization state of the liquid crystal layer.

Accordingly, when the transverse electric field type liquid crystal display device according to the first embodiment of the present invention is viewed from a diagonal direction, the polarization state of light passing through each optical element is first determined by the biaxial TAC which is the first optical compensation film. From point B to point B, from the point B to the point C by the liquid crystal layer with a phase delay value of 280-350 nm, and finally to the point A by the positive C plate, the second optical compensation film. do. Therefore, the polarization state of the light reaching the upper polarizer is coincident with the absorption axis A of the upper polarizer, and the light is blocked, thereby showing an excellent dark state.

As described above, in the first embodiment of the present invention, the polarization state is adjusted by using the biaxial TAC, the liquid crystal layer, and the positive C plate in order, thereby preventing light leakage and preventing the decrease of the contrast ratio.

In addition, the positive C plate can simplify the polarizer structure by replacing the role of the overcoat layer of the color filter substrate.

8A and 8B are diagrams showing results of simulation of luminance viewing angle characteristics and contrast ratio characteristics in a dark state in the transverse electric field type liquid crystal display device according to the first embodiment of the present invention.

As shown in the figure, it can be seen that the light leakage phenomenon is significantly reduced, unlike the conventional structure, the image quality is improved at a wide viewing angle as it has a high contrast ratio.

FIG. 9 is a cross-sectional view schematically illustrating a transverse electric field liquid crystal display device including an optical compensation film according to a second embodiment of the present invention, and a phase in an upper polarizing plate for the transverse electric field liquid crystal display device according to the first embodiment. It shows the case where TAC is configured instead of 0-RT TAC with no delay value.

As shown in the figure, the lateral field type liquid crystal table market value 200 according to the second embodiment of the present invention is positioned below the liquid crystal display panel 210 and the liquid crystal display panel 210 for outputting an image. The first polarizing plate 205 and the second polarizing plate 215 are disposed on the liquid crystal display panel 210.

In this case, the liquid crystal display panel 210 includes a color filter substrate 201 and an array substrate 211 and a liquid crystal layer 240 formed between the color filter substrate 201 and the array substrate 211.

As described above, in the case of the second embodiment of the present invention, a transverse electric field type liquid crystal display device is described as an example. However, the present invention is not limited thereto, and the present invention may be applied to the FFS mode liquid crystal display device.

The color filter substrate 201 distinguishes between the color filter 207 composed of a plurality of sub-color filters and the sub-color filter, which implements the colors of red, green, and blue, and transmits light passing through the liquid crystal layer 240. It consists of a blocking black matrix (not shown).

Further, although not shown in the drawing, the array substrate 211 is a thin film transistor that is a switching element formed in a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, and intersecting regions of the gate lines and data lines. And a pixel electrode and a common electrode formed on the pixel region to generate a transverse electric field.

The first polarizer 205 includes a first polarizer 203 and a first optical compensation film 220 positioned between the first polarizer 203 and the liquid crystal display panel 210. The second polarizer 215 includes a second polarizer 213 and a support 212 ′ disposed between the second polarizer 213 and the liquid crystal display panel 210.

In this case, the first polarizer 203 and the second polarizer 213 may be made of PVA, and the support 212 ′ may be made of a general protective film without phase delay to protect the PVA layer. In the case of the second embodiment, it may be made of TAC.

The first polarizing element 203 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarizing element 213 facing each other, that is, the optical axis of the liquid crystal layer 240, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizer 203.

In addition, the second optical compensation film 230 of the present invention is formed on the color filter substrate 201 instead of the overcoat layer for reducing the step of the color filter 207. In this case, the second embodiment of the present invention As in the case of the first embodiment, the second optical compensation film 230 is positioned between the color filter 207 and the liquid crystal layer 240 of the color filter substrate 201.

In the case of the second embodiment of the present invention, the first optical compensation film 220 and the second optical inside the first polarizing plate 205 and the liquid crystal display panel 210 in order to improve the viewing angle characteristic in the diagonal direction. Compensation film 230 is disposed, wherein the first optical compensation film 220 is formed of a biaxial TAC of 0.1≤Nz≤0.5 while the second optical compensation film 230 is 40≤Rth≤130nm. It is characterized by forming a positive C plate.

As described above, the biaxial TAC according to the second embodiment of the present invention is an optical compensation film having 0.1 ≦ Nz ≦ 0.5, and an in-plane retardation Re may have a value of 100 ≦ Re ≦ 150 nm, and the positive C plate may have the first Unlike the case of the embodiment, as the support 212 ′ uses a TAC having 1≤Re≤2nm and 20≤Rth≤60nm instead of 0-RT TAC, the phase difference Rth in the thickness direction is 40≤Rth≤130nm. Have.

The first optical compensation film 220 and the second optical compensation film 230 according to the second embodiment of the present invention having such an optical condition are formed of the first and second polarizing plates 205 and 215 in diagonal directions. By compensating for breaking of orthogonality, light leakage in the diagonal direction can be reduced.

FIG. 10 is a view showing a Poangcurry sphere showing polarization states of light passing through each optical element in the transverse electric field type liquid crystal display device according to the second embodiment of the present invention having the structure of FIG. In the case of diagonal view, Poangcurry district is shown.

Referring to FIG. 10, the polarization state of incident light passing through the lower polarizer corresponds to point P, and the polarization state of light absorbed and blocked by the absorption axis of the upper polarizer corresponds to point A. FIG.

As described above, in the transverse electric field type liquid crystal display device, light leakage off the axis in the diagonal direction is caused by a mismatch between the points P and A. Therefore, the optical compensation film according to the second embodiment of the present invention is used to cause a change in the polarization state of incident light from point P to point A, including a change in the polarization state of the liquid crystal layer.

Accordingly, when the transverse electric field type liquid crystal display device according to the second embodiment of the present invention is viewed from a diagonal direction, the polarization state of light passing through each optical element is first determined by the biaxial TAC as the first optical compensation film. It moves from point B to point B, and from point B to point C by the liquid crystal layer having a phase delay value of 280 to 350 nm. The second optical compensation film, the positive C plate, moves from the C point to the T point, and finally moves to the A point by the TAC located in the upper polarizer. Therefore, the polarization state of the light reaching the upper polarizer is coincident with the absorption axis A of the upper polarizer, and the light is blocked, thereby showing an excellent dark state.

As described above, in the second embodiment of the present invention, the polarization state is adjusted by using the biaxial TAC, the liquid crystal layer, the positive C plate, and the TAC in turn, thereby preventing light leakage and preventing a decrease in contrast ratio.

In addition, the positive C plate can simplify the polarizer structure by replacing the role of the overcoat layer of the color filter substrate.

In addition, the transverse electric field liquid crystal display device of the first embodiment and the transverse electric field liquid crystal display device of the second embodiment are further polarized by applying a biaxial TAC including a TAC for protecting PVA, which is a polarizing element, to the lower polarizing plate. The structure of the can be simplified.

11A and 11B are diagrams illustrating simulation results of luminance viewing angle characteristics and contrast ratio characteristics in a transverse electric field type liquid crystal display device according to a second exemplary embodiment of the present invention. It can be seen that it is significantly reduced, and the image quality is improved with a wide viewing angle as it has a high contrast ratio.

Such a transverse electric field type liquid crystal display device of the present invention can be positioned in the color filter substrate or the upper polarizing plate positive C plate, which is the second optical compensation film in various ways through the following third to sixth embodiments Explain.

12 is a cross-sectional view schematically showing a transverse electric field type liquid crystal display device including an optical compensation film according to a third embodiment of the present invention, wherein a positive C plate, which is a second optical compensation film, is positioned between a color filter substrate and a color filter. The case where it was made is shown, for example.

As shown in the figure, the transverse electric field type liquid crystal display device 300 according to the third embodiment of the present invention includes a liquid crystal display panel 310 for outputting an image and a lower portion of the liquid crystal display panel 310. The first polarizing plate 305 and the second polarizing plate 315 are disposed on the liquid crystal display panel 310.

In this case, the liquid crystal display panel 310 includes a color filter substrate 301 and an array substrate 311 and a liquid crystal layer 340 formed between the color filter substrate 301 and the array substrate 311.

The color filter substrate 301 distinguishes between the color filter 307 composed of a plurality of sub-color filters and the sub-color filter that implements red, green, and blue colors, and transmits light passing through the liquid crystal layer 340. It consists of a blocking black matrix (not shown).

In addition, although not shown in the drawing, the array substrate 311 is a thin film which is a switching element formed in a cross region of the gate line and the data line and the gate line and the data line, which are arranged in a vertical direction and define a plurality of pixel regions. A pixel electrode and a common electrode formed over the transistor and the pixel region to generate a transverse electric field.

The first polarizer 305 is formed of a first polarizer 303 and a first optical compensation film 320 positioned between the first polarizer 303 and the liquid crystal display panel 310. The second polarizer 315 includes a second polarizer 313 and a support 312 positioned between the second polarizer 313 and the liquid crystal display panel 310.

In this case, the first polarizer 303 and the second polarizer 313 may be made of PVA, the support 312 may be made of a general protective film without phase delay to protect the PVA layer, In the case of the third embodiment, it may consist of a 0-RT TAC or a general TAC.

The first polarization element 303 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarization element 313 facing each other, that is, the optical axis of the liquid crystal layer 340, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizer 303.

In addition, the second optical compensation film 330 of the present invention is formed on the color filter substrate 301. In this case, the third embodiment of the present invention is different from the case of the first and second embodiments. The second optical compensation film 330 is positioned between the glass substrate of the color filter substrate 301 and the color filter 307, and the level of the color filter 307 is reduced on the color filter 307. The overcoat layer 309 is located.

In the third exemplary embodiment of the present invention, the first optical compensation film 320 and the second optical are respectively formed in the first polarizing plate 305 and the liquid crystal display panel 310 in order to improve the viewing angle characteristic in the diagonal direction. The compensation film 330 is disposed, wherein the first optical compensation film 220 is formed of a biaxial TAC, while the second optical compensation film 230 is formed of a positive C plate, and the phase condition thereof. Reference may be made to the case of the first embodiment or the second embodiment.

FIG. 13 is a cross-sectional view schematically illustrating a transverse electric field type liquid crystal display device including an optical compensation film according to a fourth embodiment of the present invention, in which a positive C plate, which is a second optical compensation film, is positioned on a rear surface of a glass substrate of a color filter substrate. The case where it was made is shown, for example.

As shown in the figure, the transverse electric field type liquid crystal display device 400 according to the fourth embodiment of the present invention includes a liquid crystal display panel 410 for outputting an image and a lower portion of the liquid crystal display panel 410. The first polarizer 405 and the second polarizer 415 are disposed on the liquid crystal display panel 410.

In this case, the liquid crystal display panel 410 is composed of a color filter substrate 401 and an array substrate 411 and a liquid crystal layer 440 formed between the color filter substrate 401 and the array substrate 411.

The color filter substrate 401 distinguishes between the color filter 407 composed of a plurality of sub-color filters and the sub-color filter, which implements the colors of red, green, and blue, and transmits light passing through the liquid crystal layer 440. It consists of a blocking black matrix (not shown).

Further, although not shown in the drawing, the array substrate 411 is a thin film transistor that is a switching element formed in a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, and intersecting regions of the gate lines and data lines. And a pixel electrode and a common electrode formed on the pixel region to generate a transverse electric field.

The first polarizer 405 includes a first polarizer 403 and a first optical compensation film 420 positioned between the first polarizer 403 and the liquid crystal display panel 410. The second polarizer 415 includes a second polarizer 413 and a support 412 positioned between the second polarizer 413 and the liquid crystal display panel 410.

In this case, the first polarizer 403 and the second polarizer 413 may be made of PVA, the support 412 may be made of a general protective film without phase delay to protect the PVA layer, In the case of the fourth embodiment, it may be made of a 0-RT TAC or a general TAC.

The first polarization element 403 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarization element 413 facing each other, and that is, the optical axis of the liquid crystal layer 440, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizer 403.

In addition, the second optical compensation film 430 of the present invention is formed on the color filter substrate 401. In this case, the fourth embodiment of the present invention is different from the first to third embodiments. The second optical compensation film 430 is positioned on a rear surface of the glass substrate of the color filter substrate 401, and the overcoat layer 409 is disposed on the color filter 407 to reduce the step of the color filter 407. It is characterized by being located.

That is, although not shown in the drawing, the rear surface ITO is formed on the rear surface of the glass substrate of the color filter substrate 401 of the transverse electric field type liquid crystal display device 400, and the glass substrate and the rear surface ITO of the color filter substrate 401 are formed. The second optical compensation film 430 is positioned in between.

In the fourth exemplary embodiment of the present invention, the first optical compensation film 420 and the second optical inside the first polarizing plate 405 and the liquid crystal display panel 410, respectively, in order to improve the viewing angle characteristic in the diagonal direction. Compensation film 430 is disposed, wherein the first optical compensation film 420 is formed of a biaxial TAC while the second optical compensation film 430 is formed of a positive C plate, the phase condition Reference may be made to the case of the first embodiment or the second embodiment.

FIG. 14 is a cross-sectional view schematically illustrating a transverse electric field type liquid crystal display device including an optical compensation film according to a fifth embodiment of the present invention, wherein a positive C plate, which is a second optical compensation film, is disposed between a color filter and an overcoat layer. The case is shown for example.

As shown in the figure, the transverse electric field type liquid crystal display device 500 according to the fifth embodiment of the present invention is positioned below the liquid crystal display panel 510 for outputting an image and the liquid crystal display panel 510. The first polarizer 505 and the second polarizer 515 are disposed on the liquid crystal display panel 510.

In this case, the liquid crystal display panel 510 includes a color filter substrate 501 and an array substrate 511, and a liquid crystal layer 540 formed between the color filter substrate 501 and the array substrate 511.

The color filter substrate 501 distinguishes between a color filter 507 composed of a plurality of sub-color filters and a sub-color filter that implements red, green, and blue colors, and transmits light passing through the liquid crystal layer 540. It consists of a blocking black matrix (not shown).

In addition, although not shown in the drawing, the array substrate 511 is a thin film transistor that is a switching element formed in a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, and intersecting the gate lines and data lines. And a pixel electrode and a common electrode formed on the pixel region to generate a transverse electric field.

The first polarizer 505 is composed of a first polarizer 503 and a first optical compensation film 520 positioned between the first polarizer 503 and the liquid crystal display panel 510. The second polarizer 515 may include a second polarizer 513 and a support 512 positioned between the second polarizer 513 and the liquid crystal display panel 510.

In this case, the first polarizer 503 and the second polarizer 513 may be made of PVA, the support 512 may be made of a general protective film without phase delay to protect the PVA layer, In the case of the fifth embodiment, it may be a 0-RT TAC or a general TAC.

The first polarization element 503 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarization element 513 facing each other, that is, the optical axis of the liquid crystal layer 540, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizer 503.

In addition, the second optical compensation film 530 of the present invention is formed on the color filter substrate 501. In this case, the fifth embodiment of the present invention is different from the first to fourth embodiments. The second optical compensation film 530 is positioned on the color filter 507 of the color filter substrate 501, and the overcoat layer 509 is positioned on the second optical compensation film 530. .

That is, the second optical compensation film 530 according to the fifth embodiment of the present invention is positioned between the color filter 507 and the overcoat layer 509 of the color filter substrate 501.

In the case of the fifth embodiment of the present invention, the first optical compensation film 520 and the second optical inside the first polarizing plate 505 and the liquid crystal display panel 510, respectively, in order to improve the viewing angle characteristic in the diagonal direction. Compensation film 530 is disposed, wherein the first optical compensation film 520 is formed of a biaxial TAC while the second optical compensation film 530 is formed of a positive C plate, the phase condition Reference may be made to the case of the first embodiment or the second embodiment.

FIG. 15 is a cross-sectional view schematically illustrating a transverse electric field type liquid crystal display device including an optical compensation film according to a sixth embodiment of the present invention, in which a positive C plate as a second optical compensation film is formed in an upper polarizing plate. For example, it is shown.

As shown in the drawing, the transverse electric field type liquid crystal display device 600 according to the sixth exemplary embodiment of the present invention includes a liquid crystal display panel 610 for outputting an image and a lower portion of the liquid crystal display panel 610. The first polarizer 605 and the second polarizer 615 are disposed on the liquid crystal display panel 610.

In this case, the liquid crystal display panel 610 is composed of a color filter substrate 601 and an array substrate 611 and a liquid crystal layer 640 formed between the color filter substrate 601 and the array substrate 611.

The color filter substrate 601 distinguishes between the color filter 607 composed of a plurality of sub-color filters that implements red, green, and blue colors and the sub-color filter, and transmits light passing through the liquid crystal layer 640. It consists of a blocking black matrix (not shown).

In addition, although not shown in the drawing, the array substrate 611 is a thin film transistor that is a switching element formed in a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, and intersecting the gate lines and data lines. And a pixel electrode and a common electrode formed on the pixel region to generate a transverse electric field.

The first polarizer 605 includes a first polarizer 603 and a first optical compensation film 620 positioned between the first polarizer 603 and the liquid crystal display panel 610. The second polarizing plate 615 includes a second polarizing element 613 and a support 612, and a second optical compensation film 630 positioned between the support 612 and the liquid crystal display panel 610. .

In this case, the first polarizer 603 and the second polarizer 613 may be made of PVA, the support 612 may be made of a general protective film without phase delay to protect the PVA layer, In the case of the sixth embodiment, it may be made of a 0-RT TAC or a general TAC.

The first polarizing element 603 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarizing element 613 facing each other, that is, the optical axis of the liquid crystal layer 640, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizer 603.

In the sixth exemplary embodiment of the present invention, the first optical compensation film 620 and the second optical compensation are respectively provided in the first polarizing plate 605 and the second polarizing plate 615 in order to improve the viewing angle characteristic in the diagonal direction. The film 630 is disposed, wherein the first optical compensation film 620 is formed of a biaxial TAC while the second optical compensation film 630 is formed of a positive C plate, and the phase condition is Reference may be made to the case of the first embodiment or the second embodiment.

As described above, in the transverse electric field type liquid crystal display device according to the third to sixth embodiments of the present invention, the positive C plate, which is the second optical compensation film, may be formed in different positions. Even though the formed positions are different, simulation results of the luminance viewing angle characteristic of the dark state are the same, and thus light leakage can be prevented in the diagonal viewing angle direction.

FIG. 16 is a cross-sectional view schematically illustrating a transverse electric field type liquid crystal display device including an optical compensation film according to a seventh embodiment of the present invention. An example of using a biaxial compensation film and a 0-RT TAC simultaneously in a lower polarizer It is shown.

As shown in the figure, the transverse electric field type liquid crystal display device 700 according to the seventh exemplary embodiment of the present invention includes a liquid crystal display panel 710 for outputting an image and a lower portion of the liquid crystal display panel 710. The first polarizing plate 705 and the second polarizing plate 715 are disposed on the liquid crystal display panel 710.

In this case, the liquid crystal display panel 710 includes a color filter substrate 701 and an array substrate 711, and a liquid crystal layer 740 formed between the color filter substrate 701 and the array substrate 711.

The color filter substrate 701 distinguishes between the color filter 707 and the sub-color filter composed of a plurality of sub-color filters for implementing red, green, and blue colors, and transmits light passing through the liquid crystal layer 740. It consists of a blocking black matrix (not shown).

In addition, although not shown in the drawing, the array substrate 711 is a thin film transistor which is a switching element formed in a plurality of gate lines and data lines arranged vertically and horizontally to define a plurality of pixel regions, and intersecting the gate lines and data lines. And a pixel electrode and a common electrode formed on the pixel region to generate a transverse electric field.

The first polarizer 705 may include a first polarizer 703 and a first support 702, and a first optical compensation film 720 ′ disposed between the first support 702 and the liquid crystal display panel 710. Consists of The second polarizer 715 includes a second polarizer 713 and a second support 712 positioned between the second polarizer 713 and the liquid crystal display panel 710.

In this case, the first polarizer 703 and the second polarizer 713 may be made of PVA, and the first support 702 and the second support 712 are phase delayed to protect the PVA layer. It can be made of a common protective film. In this case, in the case of the seventh embodiment, the first support 702 may be made of 0-RT TAC, and the second support 712 may be made of 0-RT TAC or general TAC.

The first polarizing element 703 is disposed such that its absorption axis is substantially orthogonal to the absorption axis of the second polarizing element 713 facing each other, and that is, the optical axis of the liquid crystal layer 740, that is, The rubbing direction is substantially perpendicular to the light absorption axis of the first polarizer 703.

The second optical compensation film 730 of the present invention is formed on the color filter substrate 701, between the color filter 707 and the liquid crystal layer 740 of the color filter substrate 701. The optical compensation film 730 is positioned.

In the seventh exemplary embodiment of the present invention, the first optical compensation film 720 ′ and the second optical compensation film 720 ′ and the second polarizing plate 705 and the liquid crystal display panel 710 are respectively disposed in order to improve the viewing angle characteristic in the diagonal direction. The optical compensation film 730 is disposed, wherein the first optical compensation film 720 'is formed of a biaxial compensation film while the second optical compensation film 730 is formed of a positive C plate. The phase condition may refer to the case of the first embodiment or the second embodiment.

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 defined by the described embodiments, but should be defined by the claims and their equivalents.

1 is a plan view schematically illustrating a portion of an array substrate of a general transverse electric field type liquid crystal display device;

FIG. 2 is an exemplary view showing a cross section taken along line II ′ of the array substrate shown in FIG. 1. FIG.

FIG. 3A is a view showing a result of simulating a luminance viewing angle characteristic in a dark state in a general transverse electric field type liquid crystal display device. FIG.

3B is a view showing a result of simulating a contrast ratio characteristic of a dark state in a general transverse electric field type liquid crystal display device.

4A is an exemplary view schematically showing a light transmission axis of an orthogonal upper and lower polarizing plate when viewed from the front.

4B is an exemplary view schematically showing the light transmission axes of the upper and lower polarizing plates that are perpendicular to each other when viewed in a diagonal direction.

5 is a cross-sectional view schematically showing a transverse electric field type liquid crystal display device including an optical compensation film according to a first embodiment of the present invention.

6A and 6B are diagrams showing arbitrary elliptical polarizations and corresponding poangcurry vectors in a rectangular coordinate system.

FIG. 7 is a view showing a Poangcurry sphere showing a polarization state of light passing through each optical element in the transverse electric field type liquid crystal display device according to the first embodiment of the present invention having the structure of FIG. 5.

8A and 8B are diagrams showing results of simulating luminance viewing angle characteristics and contrast ratio characteristics in a dark state in a transverse electric field type liquid crystal display device according to a first embodiment of the present invention.

9 is a cross-sectional view schematically showing a transverse electric field type liquid crystal display device including an optical compensation film according to a second embodiment of the present invention.

FIG. 10 is a view showing a Poangcurry sphere showing the polarization state of light passing through each optical element in the transverse electric field type liquid crystal display device according to the second embodiment of the present invention having the structure of FIG.

11A and 11B are diagrams showing results of simulating luminance viewing angle characteristics and contrast ratio characteristics in a dark state in a transverse electric field type liquid crystal display device according to a second embodiment of the present invention.

12 is a cross-sectional view schematically showing a transverse electric field type liquid crystal display device including an optical compensation film according to a third embodiment of the present invention.

13 is a schematic cross-sectional view of a transverse electric field type liquid crystal display device including an optical compensation film according to a fourth embodiment of the present invention.

14 is a cross-sectional view schematically showing a transverse electric field type liquid crystal display device including an optical compensation film according to a fifth embodiment of the present invention.

15 is a schematic cross-sectional view of a transverse electric field type liquid crystal display device including an optical compensation film according to a sixth embodiment of the present invention.

FIG. 16 is a cross-sectional view schematically illustrating a transverse electric field liquid crystal display device including an optical compensation film according to a seventh embodiment of the present invention. FIG.

** Explanation of symbols for main parts of drawings **

100 to 700: liquid crystal display 101 to 701: color filter substrate

103 to 703: first polarizer 105 to 705: first polarizer

107 ~ 707: Color filter 110 ~ 710: Liquid crystal display panel

111 to 711: array substrate 113 to 713: second polarizer

115 to 715: second polarizer 120 to 620, 720: first optical compensation film

130 to 730: second optical compensation film 140 to 740: liquid crystal layer

Claims (14)

A liquid crystal display panel including a color filter substrate and an array substrate including a color filter, and a liquid crystal layer formed between the color filter substrate and the array substrate; A first polarizing plate disposed under the liquid crystal display panel and including a first polarizing element and a first optical compensation film positioned between the first polarizing element and the liquid crystal display panel; And A second polarizing plate positioned on the liquid crystal display panel, the second polarizing plate including a second polarizing element and a support positioned between the second polarizing element and the liquid crystal display panel; The first optical compensation film is defined as 0.1≤Nz≤0.5 (where Nz = Rth / Re, Re = (nx-ny) · d and Rth = (nx-nz) · d, and the nx, ny and nz Is a refractive index in the x direction, the y direction and the z direction, respectively, and d means the thickness of the film), and the second axis made of a positive C plate between the liquid crystal layer and the second polarizing plate Transverse electric field type liquid crystal display device comprising an optical compensation film, characterized in that the optical compensation film is located. The transverse electric field liquid crystal display device of claim 1, wherein an absorption axis of the first polarizer and an absorption axis of the second polarizer are perpendicular to each other. The transverse electric field liquid crystal display device of claim 2, wherein the optical axis of the liquid crystal layer is perpendicular to the absorption axis of the first polarizer. The transverse electric field liquid crystal display device of claim 1, wherein the biaxial compensation film is formed of a biaxial TAC, and Re has a phase delay value of about 100 nm to 150 nm. The optical support film of claim 1, wherein the support is made of triacetyl cellulose (TAC) having Re of 1 to 2 nm and Rth of about 20 to 60 nm. Transverse electric field liquid crystal display device. 6. The transverse electric field liquid crystal display device according to claim 5, wherein the positive C plate has a phase delay value of about 10 to 100 nm in Rth. The transverse electric field liquid crystal display device of claim 1, wherein the support is made of a 0-RT TAC (TAC whose Rth is close to 0 nm). The transverse electric field liquid crystal display device of claim 7, wherein the positive C plate has a phase delay value of about 40 nm to about 130 nm. The transverse electric field liquid crystal display device of claim 1, wherein the positive C plate is positioned between the color filter and the liquid crystal layer of the color filter substrate. The transverse electric field liquid crystal display device of claim 1, wherein the positive C plate is positioned between the glass substrate of the color filter substrate and the color filter. The transverse electric field liquid crystal display device of claim 1, wherein the positive C plate is positioned on a rear surface of the glass substrate of the color filter substrate. 10. The transverse electric field liquid crystal display device according to claim 9, further comprising an overcoat layer formed between the positive C plate and the liquid crystal layer. The transverse field type liquid crystal display market value of claim 1, wherein the positive C plate is positioned between the support and the liquid crystal display panel. The transverse electric field liquid crystal display device of claim 1, further comprising a 0-RT TAC positioned between the biaxial compensation film and the first polarizer.

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