KR102168874B1 - Liquid crystal display device - Google Patents

Abstract

The present invention improves display quality by reducing the electric field in the non-display area between adjacent subpixels to prevent color mixing at the side, and at the same time, misalignment between the thin film transistor array substrate and the color filter array substrate occurs, resulting in a bonding failure. A liquid crystal display device capable of preventing light leakage, wherein a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer interposed therebetween, wherein the thin film transistor array substrate is on a first substrate. A thin film transistor formed for each of a plurality of subpixels having a matrix shape defined by crossing the gate line and the data line; A protective film formed to cover the thin film transistor; A pixel electrode formed on the protective film and connected to the thin film transistor; And a common electrode overlapping the pixel electrode with an insulating layer therebetween, and formed to a region overlapping the data line, wherein the color filter array substrate is formed of an opaque conductive material on the second substrate, It includes an overlapping black matrix, and a vertical electric field is generated between the black matrix and the common electrode.

Description

Liquid crystal display device {LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a liquid crystal display device, and relates to a liquid crystal display device capable of preventing color mixture from side surfaces to improve display quality and prevent front light leakage.

As the information society develops, the demand for display devices is increasing in various forms. Display) and other flat panel display devices have been studied, and some are already used as display devices in various equipment.

Among them, the liquid crystal display device includes a color filter array substrate on which a color filter is formed, a thin film transistor array substrate on which a thin film transistor is formed, and a liquid crystal layer formed between the color filter array substrate and the thin film transistor array substrate. In the thin film transistor array substrate, a gate line and a data line cross each other to define a subpixel, and a thin film transistor is formed in each subpixel. The color filters formed on the color filter array substrate are formed to correspond to each subpixel, and as the thin film transistor is driven, light of a color corresponding to each color filter is realized. The color filter array substrate is provided with a black matrix to correspond to a non-display area in which a thin film transistor, a gate line, a data line, etc. are formed, to prevent light leakage in the non-display area.

In particular, in the case of a fringe electric field mode liquid crystal display in which a pixel electrode connected to a thin film transistor overlaps a common electrode between an insulating film to generate a fringe electric field, it is also common between adjacent subpixels corresponding to the data wiring to improve the front transmittance. To form an electrode. In the fringe electric field mode liquid crystal display as described above, a fringe electric field is formed in a central portion of a pixel region where the pixel electrode and the common electrode overlap, and a lateral electric field is generated around the data line. That is, the liquid crystal around the sub-pixel is also rotated by the transverse electric field generated as described above, thereby improving the front transmittance.

However, when the liquid crystal display is viewed from the side while the liquid crystal rotates due to the lateral electric field, color mixture occurs due to the color filters of adjacent sub-pixels, resulting in deterioration of display quality. For example, when red, green, and blue subpixels with red, green, and blue color filters are provided in a matrix form, driving only the red subpixels will The liquid crystal rotates by the generated transverse electric field. Thus, red light is mixed with blue light and green light of adjacent subpixels.

The present invention has been conceived to solve the above problems, and reduces the electric field between adjacent sub-pixels corresponding to the data line to prevent color mixing at the side to improve display quality, and at the same time, a thin film transistor array substrate and a color filter array Provided is a liquid crystal display device capable of preventing light leakage even when a misalignment of a substrate occurs and a bonding failure occurs, and there is an object thereof.

The liquid crystal display of the present invention for achieving the above object is a liquid crystal display in which a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer interposed therebetween, wherein the thin film transistor array substrate is on a first substrate. A thin film transistor formed for each of a plurality of subpixels having a matrix shape defined by crossing the gate line and the data line; A protective film formed to cover the thin film transistor; A pixel electrode formed on the protective film and connected to the thin film transistor; And a common electrode overlapping the pixel electrode with an insulating layer therebetween, and formed to a region overlapping the data line, wherein the color filter array substrate is formed of an opaque conductive material on the second substrate, It includes an overlapping black matrix, and a vertical electric field is generated between the black matrix and the common electrode.

The vertical electric field prevents the liquid crystal of the liquid crystal layer from rotating due to a lateral electric field generated by the common electrode and the pixel electrode in a region of the thin film transistor array substrate corresponding to the data line.

In addition, in a liquid crystal display according to another embodiment of the present invention, in a liquid crystal display in which a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer therebetween, the thin film transistor array substrate is on the first substrate. A thin film transistor formed for each of a plurality of subpixels having a matrix shape defined by crossing the gate line and the data line; A protective film formed to cover the thin film transistor; A pixel electrode formed on the protective film and connected to the thin film transistor; And a common electrode overlapping the pixel electrode with an insulating layer therebetween and formed to a region overlapping the data line, wherein the color filter array substrate is formed on the second substrate to provide an additional electrode overlapping the data line. And a vertical electric field is generated between the additional electrode and the common electrode.

The vertical electric field prevents the liquid crystal of the liquid crystal layer from rotating due to a lateral electric field generated by the common electrode and the pixel electrode in a region of the thin film transistor array substrate corresponding to the data line.

The color filter array substrate is formed on the second substrate and provided to overlap the gate wiring, the data wiring, and the thin film transistor, and the color filter formed on the second substrate to correspond to the subpixel, and the black matrix And an overcoat layer formed to cover the color filter, wherein the additional electrode is formed on the overcoat layer or the color filter, or is formed on the black matrix to have the same pattern as the black matrix.

The width of the additional electrode is the same as the width of the black matrix in an area overlapping the data line.

The additional electrode is formed of an opaque conductive material or a transparent conductive material.

In addition, in a liquid crystal display according to another embodiment of the present invention, in a liquid crystal display in which a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer therebetween, the thin film transistor array substrate is on the first substrate. A thin film transistor formed for each of a plurality of subpixels having a matrix shape defined by crossing the gate line and the data line; A protective film formed to cover the thin film transistor; A pixel electrode formed on the protective film and connected to the thin film transistor; And a common electrode overlapping the pixel electrode with an insulating layer therebetween and formed to a region overlapping the data line, and is formed on at least one of the thin film transistor array substrate and the color filter array substrate, and the data A cell gap of the liquid crystal layer in a region in which the field prevention pattern is formed is smaller than a cell gap of the liquid crystal layer in the remaining region, which includes an electric field prevention pattern formed in a region corresponding to the wiring.

The strength of the electric field generated in the area where the electric field prevention pattern is formed is weaker than the strength of the electric field generated by the common electrode and the pixel electrode overlapped with the insulating layer therebetween.

The electric field prevention pattern is integrally formed with the protective layer.

The electric field prevention pattern is formed on the insulating layer.

The electric field prevention pattern is formed of an organic insulating material.

The color filter array substrate includes a second substrate, a black matrix formed on the second substrate to overlap the gate wiring, the data wiring, and the thin film transistor, and a color formed on the second substrate to correspond to the subpixels. And a filter and an overcoat layer formed to cover the black matrix and the color filter.

The electric field prevention pattern is integrally formed with the overcoat layer.

The field prevention pattern may be formed in a structure in which a plurality of fields are arranged in a line along the data line, overlap the data line, and formed in a separate structure in a region corresponding to the gate line, or the gate line and the data line It is formed to overlap and is formed in a structure surrounding the subpixels.

The liquid crystal display of the present invention as described above has the following effects.

First, by forming the black matrix of an opaque conductive material, a vertical electric field is generated by the black matrix and the common electrode in the non-display area corresponding to the data line. Since the vertical electric field prevents the lateral electric field from being generated in the periphery of the sub-pixel, rotation of the liquid crystal in the periphery of the sub-pixel is reduced to prevent lateral color mixing. In particular, by forming an additional electrode on the color filter or the overcoat layer to correspond to the data line, the above-described vertical electric field can be generated.

Second, by forming an electric field reduction pattern on the thin film transistor array substrate so as to correspond to the non-display area corresponding to the data line, a cell gap between adjacent subpixels corresponding to the data line is reduced. Accordingly, the magnitude of the transverse electric field generated between adjacent subpixels decreases, so that the transmittance is also reduced. In particular, it is possible to easily adjust the transmittance by adjusting the thickness of the electric field reduction pattern.

Third, since the lateral electric field between adjacent subpixels corresponding to the data wiring is reduced by the electric field reduction pattern, front light leakage can be prevented even if a bonding failure occurs due to misalignment between the thin film transistor array substrate and the color filter array substrate. I can.

1 is a cross-sectional view of a liquid crystal display according to a first exemplary embodiment of the present invention.
2A to 2C are cross-sectional views of a liquid crystal display according to a second exemplary embodiment of the present invention.
3A is a cross-sectional view illustrating a transmittance and an electric field of a general liquid crystal display, and FIG. 3B is a cross-sectional view illustrating a transmittance and an electric field of a liquid crystal display according to a second exemplary embodiment of the present invention.
4 is a cross-sectional view of a liquid crystal display according to a third exemplary embodiment of the present invention.
5 is a cross-sectional view illustrating transmittance and electric field of a liquid crystal display according to a third exemplary embodiment of the present invention.
6 is a cross-sectional view of a liquid crystal display according to a fourth exemplary embodiment of the present invention.
7 is a cross-sectional view of a liquid crystal display according to a fifth exemplary embodiment of the present invention.
8A to 8C are plan views of electric field reduction patterns.
9A to 9E are cross-sectional views taken along line I-I' of FIG. 8A.
10 is a graph showing transmittance of a general liquid crystal display device in which bonding failure occurs.
11 is a graph showing the transmittance of the liquid crystal display device of the present invention in which bonding failure occurs.

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

1 is a cross-sectional view of a liquid crystal display according to a first exemplary embodiment of the present invention.

1, the liquid crystal display according to the first embodiment of the present invention includes a first substrate 110, a thin film transistor (not shown) formed on the first substrate 110, a pixel electrode 130, and a common electrode ( A color filter array including a thin film transistor array substrate including 140), a second substrate 210, a black matrix 215 formed on the second substrate 210, a color filter 220, and an overcoat layer 225 It includes a substrate and a liquid crystal layer 300 between the thin film transistor array substrate and the color filter array substrate, and the black matrix 215 is formed of an opaque conductive material so that a vertical electric field is generated between the common electrode 140 and the black matrix 215. Occurs.

Specifically, in the thin film transistor array substrate, a plurality of subpixels in a matrix form are defined by crossing the gate line and the data line DL on the first substrate 110. A thin film transistor (not shown) including a gate electrode, a gate insulating film 115, a semiconductor layer, a source electrode, and a drain electrode is formed for each sub-pixel, and a protective film 125 is formed to cover the thin film transistor. The passivation layer 125 may be formed in a structure in which a first passivation layer 125a formed of an inorganic insulating material and a second passivation layer 125b formed of an organic insulating material are sequentially stacked. The first passivation layer 125a is preferably silicon oxide (SiOx), silicon nitride (SiNx), or the like, and the second passivation layer 125b is preferably a photo active compound (PAC).

A pixel electrode 130 connected to a thin film transistor (not shown) is provided on the passivation layer 125. The pixel electrode 130 is formed in the form of a current electrode, and is formed in a structure separated for each sub-pixel. An insulating layer 135 is formed to cover the pixel electrode 130. A slit-shaped common electrode 140 is formed on the insulating layer 135 to overlap the pixel electrode 130. The common electrode 140 is also formed between adjacent subpixels with the data line DL interposed therebetween to improve the front transmittance.

Although the drawing shows that the common electrode 140 is provided on the insulating layer 135, the pixel electrode 130 is provided on the insulating layer 135 and the common electrode 140 is disposed between the protective layer 125 and the insulating layer 135. It may be provided in. In this case, the common electrode 140 is formed in the form of a current electrode on the entire surface of the first substrate 110 so as to cover between adjacent subpixels, and the pixel electrode 130 is formed in a slit shape to correspond to each subpixel.

The color filter array substrate, which is bonded to the thin film transistor array substrate with the liquid crystal layer 300 therebetween, includes a second substrate 210, a black matrix 215 formed on the second substrate 210, a color filter 220, And an overcoat layer 225 and the like.

The black matrix 215 is formed to correspond to a gate line, a data line, and a thin film transistor (not shown) to prevent light leakage in a non-display area. In addition, red, green, and blue color filters 220R, 220G, and 220B are formed to correspond to each sub-pixel, and the sub-pixels on which the red, green, and blue color filters 220R, 220G, and 220B are formed are red, green, and blue. Emits light.

The color filter 220 may be formed only between adjacent black matrices 215 or may be formed so that the edge overlaps the black matrix 215. In the drawing, the color filter 220 is formed to cover the black matrix 215 It is shown that the edge of the filter 220 overlaps the black matrix 215. In addition, an overcoat layer 225 is formed on the entire surface of the second substrate 210 to cover the color filter 220 and the black matrix 215 as described above.

The black matrix 215 is formed of an opaque conductive material, for example, an opaque metal such as molybdenum, aluminum, copper, titanium, or chromium. A voltage for forming a vertical electric field with the common electrode 140 formed on the thin film transistor array substrate is applied to the black matrix 215 as described above. DC voltage or AC voltage is applied to the black matrix 215. For example, when 0V is applied as a DC voltage to the common voltage, a vertical electric field may be generated in a region corresponding to the data line by applying a voltage of 2V to the black matrix.

In general, in a liquid crystal display device, a fringe electric field is generated in a central portion of a subpixel where the pixel electrode 130 and the common electrode 140 overlap with the insulating layer 135 interposed therebetween, so that the liquid crystal rotates by the fringe electric field. In addition, a lateral electric field is generated at the periphery of the sub-pixel where the pixel electrode 130 and the common electrode 140 do not overlap. However, as described above, when the liquid crystal display is viewed from the side while the liquid crystal is rotated by the horizontal electric field, color mixture is generated by the color filters of adjacent sub-pixels, resulting in deterioration of display quality.

In the present invention, to prevent this, a voltage is applied by forming the black matrix 215 of an opaque conductive material. That is, a vertical electric field is generated between the black matrix 215 and the common electrode 140, and the generated vertical electric field is transverse by the common electrode 140 and the pixel electrode 130 at the periphery of the sub-pixel adjacent to the data line DL. Prevents the generation of electric fields. In particular, even if a horizontal electric field is generated, the liquid crystal is not sufficiently rotated around the sub-pixel adjacent to the data line DL due to the vertical electric field generated by the black matrix 215 and the common electrode 140. Even if you watch, side color mixing does not occur.

2A to 2C are cross-sectional views of a liquid crystal display according to a second exemplary embodiment of the present invention.

2A, in the liquid crystal display according to the second exemplary embodiment of the present invention, an additional electrode 230 is formed on the black matrix 215 in the same pattern as the black matrix 215. In this case, the additional electrode 230 may be formed of a transparent conductive material such as ITO or IZO, or may be formed of an opaque conductive material including an opaque metal such as molybdenum or aluminum. In particular, when the additional electrode 230 is formed of an opaque conductive material, it is possible to efficiently prevent the occurrence of color mixture when viewing the liquid crystal display from the side. The additional electrode 230 may be formed on the color filter 220 as shown in FIG. 2B or on the overcoat layer 225 as shown in FIG. 2C.

In this case, the additional electrodes 230 may be formed in a structure in which a plurality of additional electrodes 230 are arranged in a line only along the data line DL, or may be formed to overlap not only the data line DL but also the gate line GL. In addition, the width of the additional electrode 230 may be easily adjusted in consideration of transmittance. However, if the width of the additional electrode 230 is too narrow, a sufficient vertical electric field does not occur, and if the width of the additional electrode 230 is too wide, a vertical electric field is generated up to the area where the fringe electric field is formed, resulting in a decrease in front transmittance. have. Accordingly, it is preferable that the width of the additional electrode 230 is the same as the width of the black matrix 215 between adjacent subpixels, that is, in a region overlapping with the data line DL.

3A is a cross-sectional view showing the transmittance and electric field of a general liquid crystal display device, and FIG. 3B is a cross-sectional view showing the transmittance and electric field of the liquid crystal display device according to the second embodiment of the present invention, showing that an additional electrode is formed under the overcoat layer. Shown.

In a typical liquid crystal display, a horizontal electric field is generated by the common electrode 140 and the pixel electrode 130 between adjacent subpixels corresponding to the data line DL. Therefore, even if the black matrix 215 is provided as shown in FIG. 3A, the front transmittance is improved because the liquid crystal rotates at the periphery of the sub-pixel by the horizontal electric field. However, when the liquid crystal display device is viewed from the side, the color filter 220 of the adjacent sub-pixel As a result, color mixing occurs and the display quality deteriorates.

In particular, as shown in Table 1 below, as the side viewing angle increases, the side transmittance compared to the front transmittance also increases.

Side viewing angle 45° 60° 75° Side transmittance compared to front transmittance 0.91% 3.04% 6.15%

On the other hand, as shown in FIG. 3B, since a vertical electric field is generated between adjacent subpixels corresponding to the data line DL, the liquid crystal display device of the present invention generates a vertical electric field between the pixel electrode 130 and the common electrode 140. The transverse electric field generated in the is reduced. Accordingly, it is possible to reduce the transmittance of the non-display area by preventing rotation of the liquid crystal between adjacent subpixels corresponding to the data line DL. In particular, as shown in Table 2 below, even if the side viewing angle is increased, the side transmittance is low compared to the front transmittance, so that color mixing can be prevented.

Side viewing angle 45° 60° 75° Side transmittance compared to front transmittance 0.42% 1.61% 3.23%

That is, in the first and second embodiments of the present invention, the black matrix 215 is formed of an opaque conductive material, or an additional electrode 230 is provided to correspond to the data line DL to correspond to the data line DL. A vertical electric field is generated between adjacent subpixels. Accordingly, since the liquid crystal in the region corresponding to the data line DL is rotated by the horizontal electric field, side mixture color is prevented from occurring, thereby improving display quality.

4 is a cross-sectional view of a liquid crystal display according to a third embodiment of the present invention, and FIG. 5 is a cross-sectional view showing transmittance and an electric field of the liquid crystal display according to the third embodiment of the present invention. And, FIG. 6 is a cross-sectional view of a liquid crystal display according to a fourth exemplary embodiment of the present invention.

The liquid crystal display according to the third and fourth embodiments of the present invention includes an electric field reduction pattern on a thin film transistor array substrate. The electric field reduction pattern is formed between adjacent sub-pixels.

As shown in FIG. 4, in the liquid crystal display according to the third embodiment of the present invention, a second passivation layer 125b formed to cover a thin film transistor (not shown) protrudes from an upper surface of the second passivation layer 125b. The reduction pattern 125c is included, and the electric field reduction pattern 125c and the second passivation layer 125b are integrally formed.

When the electric field reduction pattern 125c is integrally formed with the passivation layer 126b, it is formed using a halftone mask or a slit mask. In this case, the protective layer 125b is formed to have different first and second thicknesses. The portion having the first thickness is a region corresponding to the central portion of the subpixel where the pixel electrode 130 and the common electrode 140 overlap with the insulating layer 135 interposed therebetween, and the portion having the second thickness is an electric field reduction pattern ( This area corresponds to 125c).

In addition, after forming the second passivation layer 125b having a constant thickness, an electric field reduction pattern 125c having a structure protruding from the upper surface of the second passivation layer 125b may be formed using an additional mask. Complexity and manufacturing costs increase.

In particular, although the drawing shows that the common electrode 140 is provided on the insulating film 135, the pixel electrode 130 is provided on the insulating film 135 and the common electrode 140 is formed of the protective film 125 and the insulating film 135. ) May be provided between. In this case, the common electrode 140 is formed in the form of a current electrode on the entire surface of the first substrate 110 to cover between adjacent subpixels, and the pixel electrode 130 is formed in a slit form to correspond to each subpixel. As the cell gap of the liquid crystal layer 300 increases, the electric field strength decreases, so that the liquid crystal in the region of the liquid crystal layer with a small cell gap rotates less than the liquid crystal in the region with a large cell gap. Accordingly, in the liquid crystal display of the present invention, since the cell gap of the liquid crystal layer 300 in the region where the electric field reduction pattern 125c is formed is smaller than the cell gap of the liquid crystal layer 300 in the remaining region, the electric field reduction pattern 125c is The electric field strength in the formed area is reduced. For example, when the thickness d of the electric field reduction pattern 125c is 0.1 μm, when the cell gap of the liquid crystal layer 300 at the center of the sub-pixel is 3.4 μm, between adjacent sub-pixels corresponding to the data line DL The cell gap of the liquid crystal layer 300 is reduced to 3,3 μm.

Accordingly, in the liquid crystal display according to the third embodiment of the present invention, the common electrode 140 is formed between adjacent sub-pixels to improve front transmittance and at the same time, reduce the degree of rotation of the liquid crystal between adjacent sub-pixels to prevent side-mixing. can do.

Specifically, as shown in FIG. 5, when the electric field reduction pattern 125c is formed in a region overlapping the data line DL, the liquid crystal layer 300 corresponding to the data line DL by the electric field reduction pattern 125c The cell gap of is smaller than the cell gap of the liquid crystal layer 300 at the center of the subpixel where the pixel electrode 130 and the common electrode 140 overlap. Accordingly, the size of the transverse electric field generated in the area corresponding to the data line DL is reduced, and thus transmittance is decreased. In particular, as shown in Table 3 below, even if the side viewing angle is increased, the side transmittance is small compared to the front transmittance, so that color mixing can be prevented.

Side viewing angle 45° 60° 75° Side transmittance compared to front transmittance 0.1% 0.945% 2.11%

6, the liquid crystal display according to the fourth exemplary embodiment includes an electric field reduction pattern 145 on an insulating layer 135. In this case, the electric field reduction pattern 145 is preferably formed of an organic insulating material to have a sufficient thickness, and is formed using an additional mask after forming the insulating layer 135.

That is, in the liquid crystal display according to the third and fourth embodiments of the present invention, the electric field reduction patterns 125c and 145 are provided on the thin film transistor array substrate, so that the cell gap of the liquid crystal layer 300 is different so that at the periphery of the subpixel. It can reduce the transverse electric field generated.

7 is a cross-sectional view of a liquid crystal display according to a fifth exemplary embodiment of the present invention.

As shown in FIG. 7, the liquid crystal display according to the fifth exemplary embodiment includes an electric field reduction pattern 225a on a color filter array substrate. The electric field reduction pattern 225a is formed between adjacent subpixels, for example, in a region corresponding to the data line DL, and is integrated with the overcoat layer 225 as shown by using a halftone mask or a slit mask. It may be formed or may be additionally formed on the overcoat layer 225 using a material different from the overcoat layer 225 using an additional mask.

In particular, although not shown, the electric field reduction patterns 125c, 145, and 225 may be formed on both the thin film transistor array substrate and the color filter array substrate.

8A to 8C are plan views of the electric field reduction pattern, and FIGS. 9A to 9E are cross-sectional views taken along line I-I' of FIG. 8A.

The electric field reduction patterns 125c, 145, and 225a are formed in a structure in which a plurality of electric field reduction patterns 125c, 145, and 225a are arranged in a line along the data line DL, as shown in FIG. 8A, or overlap the data line DL, as shown in FIG. In the region corresponding to GL), it may be formed in a separate structure. In addition, as shown in FIG. 8C, the gate line GL and the data line DL may be overlapped to each other to surround each sub-pixel. The electric field reduction patterns 125c, 145, and 225a may have a polygonal cross section as shown in FIGS. 9A to 9C, or may have a cross section including a curved surface as shown in FIGS. 9D and 9E.

10 is a graph showing transmittance of a general liquid crystal display device in which bonding failure occurs. In addition, FIG. 11 is a graph showing the transmittance of the liquid crystal display device of the present invention in which a bonding failure occurs, and shows the transmittance of the liquid crystal display device according to the third embodiment of the present invention.

In a typical liquid crystal display, when a bonding failure occurs due to misalignment between the thin film transistor array substrate and the color filter array substrate, the black matrix formed on the color filter array substrate may correspond to the center of the subpixel, not between adjacent subpixels. In this case, as shown in FIG. 10 and Table 4, light leakage occurs in the periphery of the sub-pixel, and as the degree of misalignment increases, the transmittance of the light leakage portion also increases, thereby deteriorating display quality.

Miss Alignment Degree 0㎛ (misalignment occurrence X) 1㎛ 2㎛ 3㎛ Light source transmittance 0.03% 0.11% 0.45% 1.94%

On the other hand, in the liquid crystal display of the present invention, the electric field reduction patterns 125c, 145, and 225a are provided on the thin film transistor array substrate, so that an electric field smaller than the electric field generated at the center of the sub-pixel is generated in the area corresponding to the data line DL. do. Accordingly, since a strong electric field cannot be generated between adjacent subpixels, light leakage can be prevented even if a bonding failure occurs due to misalignment between the thin film transistor array substrate and the color filter array substrate, as shown in FIGS. 11 and 5. I can. In addition, even if the misalignment degree is increased, the transmittance of the light leaking part does not increase significantly, and the transmittance of the light leaking part of a general liquid crystal display device can be improved by up to 85.6%.

Miss Alignment Degree 0㎛ (misalignment occurrence X) 1㎛ 2㎛ 3㎛ Light source transmittance 0.03% 0.07% 0.18% 0.28%

That is, in the liquid crystal display of the present invention, by forming the black matrix 215 of an opaque conductive material, the vertical electric field is generated by the black matrix 215 and the common electrode 140 in the non-display area corresponding to the data line DL. Occurs. The rotation of the liquid crystal is reduced by a horizontal electric field generated between adjacent subpixels corresponding to the data line DL by the vertical electric field. Accordingly, side mixing is prevented and display quality is improved. In particular, by forming the additional electrode 230 on the color filter 220 or the overcoat layer 225 to correspond to the data line DL, the above-described vertical electric field may be generated.

In addition, by forming the electric field reduction patterns 125c, 145, and 225a on the thin film transistor array substrate to correspond to the non-display area corresponding to the data line DL, the cell gap between adjacent subpixels corresponding to the data line DL Is reduced. Accordingly, the magnitude of the transverse electric field generated between adjacent subpixels decreases, so that the transmittance also decreases. In particular, the transmittance can be easily adjusted by adjusting the thickness of the electric field reduction patterns 125c, 145, and 225a.

In particular, since the lateral electric field between adjacent subpixels corresponding to the data line DL is reduced by the electric field reduction patterns 125c, 145, and 225a described above, misalignment between the thin film transistor array substrate and the color filter array substrate Even if bonding failure occurs, front light leakage can be prevented.

Further, although not shown, the liquid crystal display of the present invention can be applied not only to a fringe electric field mode but also to a transverse electric field mode.

On the other hand, the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention. It will be obvious to those of ordinary skill in

110: first substrate 115: gate insulating film
125: protective film 125a: first protective film
125b: second passivation layer 125c, 145, 225a: electric field reduction pattern
130: pixel electrode 135: insulating film
140: common electrode 210: second substrate
215: black matrix 220: color filter
225: overcoat layer 230: additional electrode
300: liquid crystal layer DL: data wiring
GL: gate wiring

Claims (15)

In a liquid crystal display device in which a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer therebetween,
The thin film transistor array substrate includes: a thin film transistor disposed on a first substrate for each of a plurality of subpixels in a matrix form defined by crossing a gate line and a data line;
A protective film disposed on the thin film transistor;
A pixel electrode disposed on the protective layer and connected to the thin film transistor; And
And a common electrode overlapping the pixel electrode with an insulating layer therebetween and disposed to a region overlapping the data line,
The color filter array substrate is formed of an opaque conductive material on the second substrate and includes a black matrix overlapping the data line,
A liquid crystal display device in which a voltage of a level different from a common voltage applied to the common electrode is applied to the black matrix so that a vertical electric field is generated between the black matrix and the common electrode. The method of claim 1,
The vertical electric field prevents the liquid crystal of the liquid crystal layer from rotating due to a horizontal electric field generated by the common electrode and the pixel electrode in a region of the thin film transistor array substrate corresponding to the data line. In a liquid crystal display device in which a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer therebetween,
The thin film transistor array substrate includes: a thin film transistor disposed on a first substrate for each of a plurality of subpixels in a matrix form defined by crossing a gate line and a data line;
A protective film disposed on the thin film transistor;
A pixel electrode disposed on the protective layer and connected to the thin film transistor; And
And a common electrode overlapping the pixel electrode with an insulating layer therebetween and disposed to a region overlapping the data line,
The color filter array substrate includes an additional electrode disposed on the second substrate and overlapping the data line,
A liquid crystal display in which a voltage of a level different from that of a common voltage applied to the common electrode is applied to the additional electrode so that a vertical electric field is generated between the additional electrode and the common electrode. The method of claim 2,
The vertical electric field prevents the liquid crystal of the liquid crystal layer from rotating due to a horizontal electric field generated by the common electrode and the pixel electrode in a region of the thin film transistor array substrate corresponding to the data line. The method of claim 3,
The color filter array substrate is disposed on the second substrate and includes a black matrix provided to overlap the gate line, the data line, and the thin film transistor, and the color filter and the black disposed on the second substrate to correspond to the subpixels. Including a matrix and an overcoat layer disposed to cover the color filter,
The additional electrode is disposed on the overcoat layer or the color filter, or on the black matrix to form the same pattern as the black matrix. The method of claim 5,
The width of the additional electrode is the same as the width of the black matrix in an area overlapping the data line. The method of claim 3,
The additional electrode is formed of an opaque conductive material or a transparent conductive material. In a liquid crystal display device in which a thin film transistor array substrate and a color filter array substrate are bonded to each other with a liquid crystal layer therebetween,
The thin film transistor array substrate includes: a thin film transistor disposed on a first substrate for each of a plurality of subpixels in a matrix form defined by crossing a gate line and a data line;
A protective film disposed on the thin film transistor;
A pixel electrode disposed on the protective layer and connected to the thin film transistor; And
And a common electrode overlapping the pixel electrode with an insulating layer therebetween and disposed up to a region overlapping the data line,
An electric field prevention pattern disposed on a second substrate facing the first substrate on which the data line and the common electrode are disposed, and disposed in a region corresponding to the data line,
A liquid crystal display device in which a cell gap of the liquid crystal layer in a region in which the field prevention pattern is disposed is smaller than a cell gap of the liquid crystal layer in the remaining region. The method of claim 8,
An electric field intensity generated in a region where the electric field prevention pattern is disposed is weaker than an electric field intensity generated by the common electrode and the pixel electrode overlapped with the insulating layer therebetween. delete delete The method of claim 8,
The electric field prevention pattern is formed of an organic insulating material. The method of claim 8,
The color filter array substrate is disposed on the second substrate, a black matrix disposed on the second substrate to overlap the gate line, the data line, and the thin film transistor, and disposed on the second substrate to correspond to the subpixels And an overcoat layer disposed to cover the black matrix and the color filter. The method of claim 13,
The electric field prevention pattern is integrally formed with the overcoat layer. The method of claim 8,
The field prevention patterns are arranged in a structure in which a plurality of fields are arranged in a row along the data line, overlap with the data line, and are arranged in a separate structure in a region corresponding to the gate line, or between the gate line and the data line The liquid crystal display is arranged to overlap and surround the sub-pixels.

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