KR20070019878A - Liquid crystal display - Google Patents

Abstract

The liquid crystal display according to the present invention includes a first field generating electrode having a first cutout and a second field generating electrode facing the first field generating electrode and having a second cutout, wherein the first cutout is a second cutout. Nest with.

LCD, Light Leaks, Transmittance

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY}

1 is a layout view of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a layout view of a thin film transistor array panel for the liquid crystal display of FIG. 1.

FIG. 3 is a layout view of a common electrode display panel for the liquid crystal display of FIG. 1.

FIG. 4 is a cross-sectional view of the liquid crystal display of FIG. 1 taken along the line IV-IV'-IV ''.

FIG. 5 is a cross-sectional view illustrating an arrangement of an equipotential line and liquid crystal molecules near a horizontal cut portion or a horizontal portion of a cut portion of a conventional liquid crystal display.

6 to 8 are cross-sectional views illustrating an arrangement of equipotential lines and liquid crystal molecules near a horizontal cutout of a liquid crystal display according to an exemplary embodiment of the present invention.

9 and 10 are schematic layout views of a liquid crystal display according to another exemplary embodiment of the present invention.

※ Explanation of main symbols in drawings ※

11, 21: alignment film 7: notch

71, 72, 75, 76, 77, 78, 91, 92, 93, 94, 95, 96: incision

81, 82: contact auxiliary member

110 and 210: insulated substrate 121: gate line

151: semiconductors 163 and 165: ohmic contacts

171: data lines 181, 182, and 185: contact holes

191: pixel electrode 220: light blocking member

230: color filter 250: overcoat

270 common electrode

The present invention relates to a liquid crystal display device.

The liquid crystal display is one of the most widely used flat panel display devices and includes two display panels on which electric field generating electrodes, such as a pixel electrode and a common electrode, are formed, and a liquid crystal layer interposed therebetween. The liquid crystal display generates an electric field in the liquid crystal layer by applying a voltage to the field generating electrode, thereby determining an orientation of liquid crystal molecules of the liquid crystal layer and controlling the polarization of incident light to display an image.

Among the liquid crystal display devices, a vertically aligned mode liquid crystal display in which liquid crystal molecules are arranged such that their major axes are perpendicular to the display panel without an electric field applied to the liquid crystal display device is gaining attention due to its high contrast ratio and wide reference viewing angle.

As a means for implementing a wide viewing angle in a vertical alignment liquid crystal display, there is a method of forming an incision in the field generating electrode.

However, in the case of the liquid crystal display including the diagonal cutout and the horizontal cutout, the liquid crystal array by the diagonal cutout and the alignment direction of the liquid crystal molecules by the horizontal cutout are different. In particular, when most of the liquid crystal array is arranged by the diagonal cutout in the pixel, the liquid crystal molecules in the region corresponding to the horizontal cutout affect the liquid crystal molecules arranged by the diagonal cutout, so that light leakage around the horizontal cutout occurs. Transmittance is reduced.

Accordingly, an object of the present invention is to provide a liquid crystal display device which can increase transmittance by minimizing light leakage in a region corresponding to the horizontal cutout.

The liquid crystal display according to the present invention for achieving the above object includes a first field generating electrode having a first cutout, and a second field generating electrode facing the first field generating electrode and having a second cutout; The first cutout overlaps the second cutout.

The second field generating electrode may further have a third cutout that makes an oblique angle with the second cutout and crosses the second field generating electrode.

The first field generating electrode may have a pair of sides substantially parallel with the third cutout.

The third incision may be bent and the second incision may pass through a bent point of the third incision.

The first field generating electrode may have a fourth cutout that is substantially parallel with the third cutout.

The width of the first cutout portion and the second cutout portion may be equal to or less than 6 μm.

Each of the first and second cutouts may include first and second portions connected in the longitudinal direction.

The first portion of the first incision faces the first portion of the second incision and is greater than the first portion of the second incision and the second portion of the first incision faces the second portion of the second incision and the second incision. It may be smaller than the second portion of the negative.

The first and second portions of the first and second cutouts may vary in width in the longitudinal direction, respectively.

The thin film transistor may further include a thin film transistor connected to the first field generating electrode, and a gate line and a data line connected to the thin film transistor.

The gate line may be substantially parallel to the first and second cutouts.

The electronic device may further include a third electric field generating electrode which is separated from the first electric field generating electrode, has a different voltage from the first electric field generating electrode, and faces the second electric field generating electrode.

The first field generating electrode and the third field generating electrode may receive different voltages obtained from one image signal.

The first field generating electrode and the third field generating electrode may be capacitively coupled.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a portion of a layer, layer, area, plate, etc. is said to be "on top" of another part, this includes not only when the other part is "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

1 is a layout view of a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 2 is a layout view of a thin film transistor array panel for the liquid crystal display of FIG. 1, and FIG. 3 is a layout view of the common electrode display panel for the liquid crystal display of FIG. 1. 4 is a cross-sectional view of the liquid crystal display of FIG. 1 taken along the line IV-IV'-IV ''.

1 to 4, a liquid crystal display according to an exemplary embodiment of the present invention includes a thin film transistor array panel 100 and a common electrode panel 200 facing each other and between the two display panels 100 and 200. The liquid crystal layer 3 is included.

First, the thin film transistor array panel 100 will be described with reference to FIGS. 1, 2, and 4.

A plurality of gate lines 121 and a plurality of storage electrode lines 131 are formed on an insulating substrate 110 made of transparent glass or plastic.

The gate line 121 transmits a gate signal and mainly extends in a horizontal direction. Each gate line 121 includes a plurality of gate electrodes 124 protruding upwards and a wide end portion 129 for connection with another layer or an external driving circuit. A gate driving circuit (not shown) for generating a gate signal may be mounted on a flexible printed circuit film (not shown) attached to the substrate 110 or directly mounted on the substrate 110, It may be integrated into the substrate 110. When the gate driving circuit is integrated on the substrate 110, the gate line 121 may extend to be directly connected to the gate driving circuit.

The storage electrode line 131 receives a predetermined voltage and almost extends in parallel with the gate line 121. Each storage electrode line 131 is positioned between two adjacent gate lines 121 and is close to a lower side of the two gate lines 121. The storage electrode line 131 includes a storage electrode 137 extending up and down. However, the shape and arrangement of the storage electrode line 131 may be modified in various ways.

The gate line 121 and the storage electrode line 131 may be formed of aluminum-based metal such as aluminum (Al) or aluminum alloy, silver-based metal such as silver (Ag) or silver alloy, copper-based metal such as copper (Cu) or copper alloy, or molybdenum ( It may be made of molybdenum-based metal such as Mo) or molybdenum alloy, chromium (Cr), tantalum (Ta) and titanium (Ti). However, they may have a multilayer structure including two conductive films (not shown) having different physical properties. One of the conductive films is made of a metal having low resistivity, such as aluminum-based metal, silver-based metal, or copper-based metal, so as to reduce signal delay or voltage drop. In contrast, other conductive films are made of other materials, particularly materials having excellent physical, chemical, and electrical contact properties with indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum-based metals, chromium, tantalum, and titanium. Good examples of such a combination include a chromium bottom film, an aluminum (alloy) top film, and an aluminum (alloy) bottom film and a molybdenum (alloy) top film. However, the gate line 121 and the storage electrode line 131 may be made of various other metals or conductors.

Side surfaces of the gate line 121 and the storage electrode line 131 are inclined with respect to the surface of the substrate 110, and the inclination angle is preferably about 30 to 80 °.

A gate insulating layer 140 made of silicon nitride (SiN _x ) or silicon oxide (SiOx) is formed on the gate line 121 and the storage electrode line 131.

On the gate insulating layer 140, a plurality of island semiconductors 154 made of hydrogenated amorphous silicon (amorphous silicon is abbreviated as a-Si), polycrystalline silicon, or the like are formed. The semiconductor 154 is positioned on the gate electrode 124 and includes an extension that covers a portion of the gate line 121 and the gate electrode 124.

A plurality of island type ohmic contacts 163 and 165 are formed on the semiconductor 154. The ohmic contacts 163 and 165 may be made of a material such as n + hydrogenated amorphous silicon in which n-type impurities such as phosphorus are heavily doped, or may be made of silicide. The ohmic contacts 163 and 165 are paired and disposed on the semiconductor 154.

Side surfaces of the semiconductor 154 and the ohmic contacts 163 and 165 are also inclined with respect to the surface of the substrate 110, and the inclination angle is about 30 to 80 °.

A plurality of data lines 171 and a plurality of drain electrodes 175 are formed on the ohmic contacts 163 and 165 and the gate insulating layer 140.

The data line 171 transmits a data voltage and mainly extends in the vertical direction to cross the gate line 121 and the storage electrode line 131. Each data line 171 includes a plurality of longitudinal portions and a plurality of short curved portions, and the vertical portion and the curved portion are alternately connected. The bent portion includes a pair of diagonal portions connected to each other to form a chevron, and the diagonal portion forms an angle of about 45 ° with the gate line 121. The vertical portion includes a source electrode 173 that crosses the gate line 121 and extends toward the gate electrode 124.

Each data line 171 also includes a wide end portion 179 for connection with other layers or external drive circuits. A data driving circuit (not shown) for generating a data voltage is mounted on a flexible printed circuit film (not shown) attached to the substrate 110, directly mounted on the substrate 110, or integrated in the substrate 110. Can be. When the data driving circuit is integrated on the substrate 110, the data line 171 may be extended to be directly connected to the data driving circuit.

The drain electrode 175 is separated from the data line 171 and faces the source electrode 173 on the gate electrode 124. Each drain electrode 175 includes one wide end 177 and the other end having a rod shape. The wide end portion 177 overlaps the sustain electrode 137 and the rod-shaped end portion is partially surrounded by the source electrode 173 bent in a U shape.

One gate electrode 124, one source electrode 173, and one drain electrode 175 together with the semiconductor 154 form one thin film transistor (TFT), and a channel of the thin film transistor. ) Is formed in the semiconductor 154 between the source electrode 173 and the drain electrode 175.

The data line 171 and the drain electrode 175 are preferably made of a refractory metal such as molybdenum, chromium, tantalum, and titanium, or an alloy thereof, and include a refractory metal film (not shown) and a low resistance conductive film. It may have a multilayer structure including (not shown). Examples of the multilayer structure include a double layer of chromium or molybdenum (alloy) lower layer and an aluminum (alloy) upper layer, and a triple layer of molybdenum (alloy) lower layer and aluminum (alloy) interlayer and molybdenum (alloy) upper layer. However, in addition to the data line 171 and the drain electrode 175, it may be made of various metals or conductors.

The side of the data line 171 and the drain electrode 175 may also be inclined at an inclination angle of about 30 ° to about 80 ° with respect to the surface of the substrate 110.

The ohmic contacts 163 and 165 exist only between the semiconductor 151 below and the data line 171 and the drain electrode 175 thereon, and lower the contact resistance therebetween. The semiconductor 154 includes portions exposed between the source electrode 173 and the drain electrode 175 and not covered by the data line 171 and the drain electrode 175.

A passivation layer 180 is formed on the data line 171, the drain electrode 175, and the exposed semiconductor 151. The passivation layer 180 may be made of an inorganic insulator or an organic insulator, and may have a flat surface. Examples of the inorganic insulator include silicon nitride and silicon oxide. The organic insulator may have photosensitivity and the dielectric constant is preferably about 4.0 or less. However, the passivation layer 180 may have a double layer structure of the lower inorganic layer and the upper organic layer so as not to damage the exposed portion of the semiconductor 151 while maintaining excellent insulating properties of the organic layer.

In the passivation layer 180, a plurality of contact holes 182 and 185 exposing the end portion 179 and the drain electrode 175 of the data line 171 are formed, respectively, and the passivation layer 180 and the gate insulating layer are formed. A plurality of contact holes 181 exposing the end portion 129 of the gate line 121 are formed at 140.

A plurality of pixel electrodes 191 and a plurality of contact assistants 81 and 82 are formed on the passivation layer 180. They may be made of a transparent conductive material such as ITO or IZO or a reflective metal such as aluminum, silver, chromium or an alloy thereof.

Each pixel electrode 191 has a pair of curved edges 191c1 and 191c2 that are substantially parallel to the bent portion of the data line 171, and a pair of horizontal edges 191t and a horizontal side that are substantially parallel to the gate line 121. It has a pair of longitudinal sides 191v substantially perpendicular to 191t and is approximately chevron-shaped. The pair of curved sides 191c1 and 191c2 include a concave left side 191c2 that meets an acute angle with the horizontal side 191t and a convex right side 191c1 that meets an obtuse angle with the horizontal side 191t. The pixel electrode 191 covers the storage electrode line 131 including the storage electrode 137 and the extension 177 of the drain electrode 175.

First and second cutouts 91 and 92 are formed in each pixel electrode 191, and the pixel electrode 191 includes a plurality of partitions by the first and second cutouts 91 and 92. Divided into.

The second cutout 92 extends horizontally to the right near the recessed vertex of the pixel electrode 191. The cutout 92 has a narrower width and two blunt arrowheads are connected to the vicinity of the center of the pixel electrode 191. The left of the two arrowheads is larger than the rest.

The first cutout 91 includes a bent portion 91c having a bent point 91cp and a horizontal portion 91t connected to the bent point 91cp of the bent portion 91c. The bent portion 91c of the first cutout 91 is substantially parallel to the bent sides 191c1 and 191c2 of the pixel electrode 191 and forms a pair of diagonal portions that are approximately 45 ° with the gate line 121 and are perpendicular to each other. Include. The bent portion 91c of the first cutout 91 bisects the pixel electrode 191 into a left half and a right half. The horizontal portion 91t becomes narrower in width, like the second cutout 92, and two blunt arrowheads are near the convex vertex 191cp of the pixel electrode 191 near the right end of the second cutout 92. It is connected form. The left of the two arrowheads is larger than the rest. The horizontal portion of the first cutout 91 may be connected to the second cutout 92, and the horizontal portion of the first cutout 91 and the second cutout 92 may be formed at the left half of the pixel electrode 191. The right half is divided into upper and lower parts, respectively.

Accordingly, the pixel electrode 191 is divided into four regions by the cutouts 91 and 92. In this case, the number of regions or the number of cutouts 91 and 92 may vary according to design factors such as the size of the pixel, the ratio of the horizontal side and the height of the pixel electrode 191, the type and characteristics of the liquid crystal layer 3, and the like. .

The pixel electrode 191 is physically and electrically connected to the drain electrode 175 through the contact hole 185 and receives a data voltage from the drain electrode 175. The pixel electrode 191 to which the data voltage is applied is formed between the two electrodes 191 and 270 by generating an electric field together with the common electrode 270 of the common electrode display panel 200 to which the common voltage is applied. The direction of the liquid crystal molecules 31 of the liquid crystal layer 3 is determined. The polarization of light passing through the liquid crystal layer 3 varies according to the direction of the liquid crystal molecules 31 determined as described above. The pixel electrode 191 and the common electrode 270 form a capacitor (hereinafter, referred to as a "liquid crystal capacitor") to maintain an applied voltage even after the thin film transistor is turned off.

The pixel electrode 191 overlaps the storage electrode line 131 including the storage electrode 137. A capacitor formed by the pixel electrode 191 and the drain electrode 175 electrically connected to the pixel electrode 191 overlapping the storage electrode line 131 is called a storage capacitor, and the storage capacitor enhances the voltage holding capability of the liquid crystal capacitor.

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 compensate for and protect the adhesion between the end portions 179 and 129 of the data line 171 and the gate line 121 and the external device.

The common electrode display panel 200 will now be described with reference to FIGS. 1, 3, and 4.

A light blocking member 220, also known as a black matrix, is formed on an insulating substrate 210 made of transparent glass, plastic, or the like. The light blocking member 220 has a plurality of openings 225 having substantially the same shape as the pixel electrode 191, and may include a portion corresponding to the thin film transistor. The light blocking member 220 prevents light leakage between the pixel electrodes 191.

A plurality of color filters 230 is also formed on the substrate 210 and the light blocking member 220. The color filter 230 is mostly present in an area surrounded by the light blocking member 230, and may extend long along the column of pixel electrodes 191. Each color filter 230 may display one of primary colors such as three primary colors of red, green, and blue.

An overcoat 250 is formed on the color filter 230 and the light blocking member 220. The overcoat 250 may be made of an (organic) insulator, which prevents the color filter 230 from being exposed and provides a flat surface. The overcoat 250 may be omitted.

The common electrode 270 is formed on the overcoat 250. The common electrode 270 is made of a transparent conductor such as ITO or IZO, and has a plurality of cutouts 71 and 72.

One set of cutouts 71 and 72 faces two pixel electrodes 191 and includes two chevron cutouts 71 and 72. Each cutout 71, 72 is a curved portion 71c, 72c having a bending point 71cp, 72cp, and a central horizontal portion 71t1, 71t2 connected to the bending point 71cp, 72cp of the bending portion 71c, 72c. , 72t1, 72t2, and at least one end horizontal portion 71t3, 72t3, 72t4 connected to the ends of the bends 71c, 72c.

The bent portions 71c and 72c of the cutout 71 are substantially parallel to the bent portion 91t of the cutout 91 of the pixel electrode 191 and the bent sides 191c1 and 191c2 of the pixel electrode 191 and the pixel electrode 191. ) Are arranged at approximately equal distances between the bent portions 91t of the cut portions 91. Each of the bent portions 71c and 72c is provided with a plurality of concave notches 7 regularly arranged at regular distances.

The central horizontal portions 71t1, 71t2, 72t1, and 72t2 of the cutouts 71 and 72 of the common electrode 270 extend from both sides of the bending points 71cp and 72cp. The center horizontal parts 71t1, 71t2, 72t1, and 72t2 face each other and face similar to the horizontal parts 91t of the cutout 91 of the pixel electrode 191. That is, the central horizontal portions 71t1, 71t2, 72t1, and 72t2 of the common electrode 270 also become narrower and have two blunt arrowheads connected thereto, and the arrowhead of the common electrode 270 and the arrowhead of the pixel electrode 191 are Face each other The right of the two arrowheads is larger than the rest.

In the pair of arrowheads facing the pixel electrode 191 and the common electrode 270, one of the two is larger than the other, and the width difference is preferably within 6 μm. These arrowheads are arranged in alternating case relations between a pair of opposing arrowheads. That is, when the arrowhead of the pixel electrode 191 is large in a pair of arrowheads, the arrowhead of the common electrode 270 is large in the arrowhead pair adjacent thereto. However, it is more preferable that the two arrowheads facing each other have the same size, and the above-described arrangement is an arrangement in which alignment errors between the thin film transistor array panel 100 and the common electrode 200 are considered. It is also desirable that the boundaries of the corresponding arrowheads coincide.

Alignment layers 11 and 21 are coated on inner surfaces of the display panels 100 and 200, and they may be vertical alignment layers. Polarizers 12 and 22 are provided on the outer surfaces of the display panels 100 and 200, and the polarization axes of the two polarizers 12 and 22 are orthogonal and one of the polarization axes is parallel to the gate line 121. desirable. In the case of a reflective liquid crystal display, one of the two polarizers 12 and 22 may be omitted.

The liquid crystal display according to the present exemplary embodiment may further include a phase retardation film (not shown) for compensating for the delay of the liquid crystal layer 3. The liquid crystal display may also include a backlight unit (not shown) for supplying light to the polarizers 12 and 22, the phase retardation film, the display panels 100 and 200, and the liquid crystal layer 3.

The liquid crystal layer 3 has negative dielectric anisotropy, and the liquid crystal molecules 31 of the liquid crystal layer 3 are aligned such that their major axes are perpendicular to the surfaces of the two display panels 100 and 200 in the absence of an electric field. . Therefore, incident light does not pass through the quadrature polarizers 12 and 22 and is blocked.

When a common voltage is applied to the common electrode 270 and a data voltage is applied to the pixel electrode 191, a primary electric field substantially perpendicular to the surfaces of the display panels 100 and 200 is generated. The liquid crystal molecules 31 change their direction in response to the electric field such that their major axis is perpendicular to the direction of the electric field. From now on, the pixel electrode 191 and the common electrode 271 will be referred to as an electric field generating electrode.

The cutout 71 of the common electrode 270 and the sides of the pixel electrode 191 distort the main electric field to determine a horizontal component that determines the inclination direction of the liquid crystal molecules 31 and a degree of lying down of the liquid crystal molecules 31. Create a vertical component. The horizontal component of the main electric field is substantially perpendicular to the sides of the cutout 71 and the sides of the pixel electrode 191.

Referring to FIG. 1, an imaginary horizontal line connecting the bending point of the curved side of the pixel electrode 191 and the cutout 71 divide the pixel electrode 191 into four sub-areas. It has two major edges defined by the bent portion of the cutout 71 and the bent side of the pixel electrode 191. Since the liquid crystal molecules 31 are mostly inclined in the direction perpendicular to the periphery on each subregion, the inclination direction is approximately four directions. As described above, when the liquid crystal molecules 31 are inclined in various directions, the reference viewing angle of the liquid crystal display becomes large.

The number of subregions may be four, six, or the like, which is possible by changing the number of cutouts 71 of the common electrode 270 or the number of bending points of the side of the pixel electrode 191.

On the other hand, the direction of the secondary electric field generated by the voltage difference between the pixel electrode 191 is perpendicular to the periphery of the subregion. Thus, the direction of the negative electric field coincides with the direction of the horizontal component of the main electric field. As a result, the negative electric field between the pixel electrodes 191 acts to strengthen the crystal in the oblique direction of the liquid crystal molecules 31.

As described above, in the pixel electrode 191 and the common electrode 270, the horizontal cutouts or horizontal portions of the cutouts are disposed to face each other. In this arrangement, light leakage is reduced. This will be described in detail with reference to FIGS. 5 to 8.

5 is a cross-sectional view illustrating an arrangement of an equipotential line and liquid crystal molecules near a horizontal cutout or a horizontal cutout (collectively referred to as a horizontal cutout) of a conventional liquid crystal display, and FIGS. 6 to 8 are embodiments of the present invention. FIG. 11 is a cross-sectional view illustrating an arrangement of an equipotential line and liquid crystal molecules near a horizontal cutout of a liquid crystal display according to an example. FIG.

In the conventional liquid crystal display illustrated in FIG. 5, the pixel electrode 191 has a horizontal cutout 90, but the common electrode 270 has no horizontal cutout. 6 to 8, horizontal cutouts 90 and 70 are formed at both the pixel electrode 191 and the common electrode 270, and horizontal cutouts 70 of the common electrode 270 and the pixel electrode 191 are illustrated in FIG. 6. , 90) width difference is 2 μm, and in FIG. 7, the width difference between the cutouts 70 and 90 of the common electrode 270 and the pixel electrode 191 is 6 μm, and the left and right symmetry are aligned. A width difference between the cutouts 90 and 70 of the electrode 270 and the pixel electrode 191 is 6 μm and is aligned asymmetrically.

First, as shown in FIG. 5, the common electrode 270 has no horizontal cutout, so that the liquid crystal molecules in the vicinity are formed only by the horizontal component generated by the horizontal cutout 90 of the pixel electrode 191. (31) is inclined under power. However, since the direction of the main horizontal component of the electric field in each subregion is an oblique direction, this vertical component disturbs the inclination direction of the liquid crystal molecules, causing light leakage.

6 to 8, since both electric field generating electrodes 191 and 270 have horizontal cutouts 90 and 70, the horizontal component generated by the two horizontal cutouts 90 and 70 is combined with the horizontal component. As a result, the liquid crystal molecules 31 are inclined. However, since horizontal components generated by the two horizontal cutouts 90 and 70 are opposite to each other, precisely, horizontal components generated by the corresponding sides of the two horizontal cutouts 90 and 70 are opposite to each other. Offset by a certain amount to reduce the size of the synthetic horizontal component (vertical component). Therefore, the liquid crystal molecules 31 near the horizontal cutouts 90 and 70 are maintained in a vertical state or are inclined along the horizontal component (sloped) direction by the diagonal cutout.

In the case of Fig. 6, the composite horizontal component is very small because the widths of the two transverse cutouts 70, 90 are almost the same and the positions of the corresponding sides are almost identical. Therefore, the liquid crystal molecules 31 are arranged vertically with respect to the surface of the substrate 110 without determining a direction in which the vertical component is relatively large and accordingly inclined. In addition, the inclined liquid crystal molecules 31 are inclined in the same or similar direction as the main inclination direction in each subregion because the inclined liquid crystal molecules 31 are more affected by the oblique component than the vertical component. Therefore, the light leakage realm gives.

In the case of FIG. 7, since the width difference between the two horizontal cutouts 70 and 90 is larger than that of FIG. 6 and the positions of the corresponding sides are much different, the composite horizontal component in the vertical direction is relatively large. However, since the vertical component is smaller than that shown in FIG. 5, the light leakage area is smaller than in FIG. 5.

In the case of FIG. 8, the width difference between the two horizontal cutouts 70 and 90 is 6 μm, as shown in FIG. 7, but the left side of the cutouts 70 and 90 is almost coincident and the right side is more displaced. The magnitude of the horizontal component in the vicinity of the right side is different. In detail, the vertical horizontal component near the right side of the cutouts 70 and 90 is large, but the vertical horizontal component near the left side of the cutouts is very small. Therefore, the amount of light leakage near the left side is very small as in the case of FIG.

Next, a liquid crystal display according to another exemplary embodiment of the present invention will be described in detail with reference to FIGS. 9 and 10.

9 and 10 are schematic layout views of a liquid crystal display according to another exemplary embodiment of the present invention.

The arrangement and layer structure of the liquid crystal display shown in FIGS. 9 to 10 may be similar to those shown in FIGS. 1 to 4.

9 and 10, one pixel electrode 191 is divided into two subpixel electrodes 191a and 191b, and each subpixel electrode 191a and 191b is associated with a corresponding transistor Qa and Qb. It is connected. The two thin film transistors Qa and Qb are connected to different gate lines 121a and 121b and to the same data line 171.

Each of the subpixel electrodes 191a and 191b illustrated in FIG. 9 is similar to the pixel electrode 191 of FIG. 1. However, only one cutout, that is, a horizontal cutout 93 and 94, is formed in each of the subpixel electrodes 191a and 191b. The two subpixel electrodes 191a and 191b are adjacent to each other in the horizontal direction and are arranged to engage the concave side and the convex side. The areas of the two subpixel electrodes 191a and 191b are different from each other, and one side is preferably about twice as large as the other side. As shown in FIG. 9, there may be various methods of changing the area in addition to the method of varying the lengths of the horizontal sides of the subpixel electrodes 191a and 191b.

The cutouts 75 and 76 of the common electrode shown in FIG. 9 are also substantially the same as those shown in FIG. 1 except that there is no notch.

In FIG. 10, each of the subpixel electrodes 191a and 191b is formed by vertically connecting two subpixel electrodes 191a and 191b of FIG. 9. Accordingly, the curved edges of each of the subpixel electrodes 191a and 191b are bent three times, and horizontal cutouts 95 and 96 are formed between the three pairs of concave and convex vertices facing each other. The bends of the common electrode cutouts 77 and 78 may also be bent three times along the bends of the subpixel electrodes 191a and 191b and have three horizontal portions that penetrate three bend points.

9 and 10, different data voltages are applied to two subpixel electrodes 191a and 191b constituting one pixel electrode 191. The voltage is applied through a driving device (not shown) connected to the display panels 100 and 200 and is obtained through the following process.

The driving device receives an input image signal corresponding to each pixel electrode 191 from an external graphic controller (not shown) and converts the input image signal into two analog data voltages corresponding to each subpixel electrode 191a and 191b. It is applied to the electrodes 191a and 191b. In this case, it is preferable to select a pair of data voltages such that the luminance when viewed from the side is the closest to the luminance when viewed from the front among the luminances (transmittances) that are applied when the data voltage is applied to each of the subpixel electrodes 191a and 191b. Do.

Many features of the liquid crystal display shown in FIGS. 1 to 4 may correspond to the liquid crystal display shown in FIGS. 9 and 10.

9 and 10, the pair of subpixel electrodes 191a and 191b may be connected to the same gate line and to different data lines. In addition, instead of the thin film transistor Qb connected to the subpixel electrode 191b, the subpixel electrodes 191a and 191b may be capacitively coupled to each other.

The cutouts 91-96 and 71-78 may be applied to the case in which the pixel electrodes 191 and the subpixel electrodes 191a and 191b have a rectangular shape.

As described above, the present invention is formed so that the horizontal cutout of the common electrode and the horizontal cutout of the pixel electrode face each other so that the arrangement of the liquid crystal molecules of the horizontal cutout does not affect the arrangement of the liquid crystal molecules by the oblique cutout. Can be minimized. Therefore, the transmittance is increased to provide a high quality liquid crystal display device.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (15)

A first field generating electrode having a first incision, and A second field generating electrode facing the first field generating electrode and having a second cutout; Including, The first cutout overlaps the second cutout Liquid crystal display. In claim 1, The second field generating electrode further includes a third cutout that forms an oblique angle with the second cutout and crosses the second field generating electrode. In claim 2, And the first field generating electrode has a pair of sides substantially parallel to the third cutout. In claim 3, The third cutout is a bent liquid crystal display device. In claim 4, And the second cutout passes through a bending point of the third cutout. The method according to any one of claims 2 to 5, And the first field generating electrode has a fourth cutout portion substantially parallel to the third cutout portion. In claim 1, The width of the first cutout and the second cutout is the same or the difference is less than 6㎛ liquid crystal display device. In claim 1, Each of the first and second cutouts includes first and second portions connected in a length direction. In claim 8, The first portion of the first incision is facing the first portion of the second incision and is greater than the first portion of the second incision, and the second portion of the first incision is the second portion of the second incision. A liquid crystal display facing and smaller than a second portion of said second cutout. In claim 9, The first and second portions of the first and second cutouts may vary in width in a length direction, respectively. In claim 1, A thin film transistor connected to the first field generating electrode, and A gate line and a data line connected to the thin film transistor Liquid crystal display further comprising. In claim 11, And the gate line is substantially parallel to the first and second cutouts. In claim 1, And a third field generating electrode separated from the first field generating electrode and having a different voltage from the first field generating electrode and facing the second field generating electrode. In claim 13, The first field generating electrode and the third field generating electrode are applied with different voltages obtained from one image signal. In claim 13, The first field generating electrode and the third field generating electrode are capacitively coupled to each other.

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