Patent Publication Number: US-9846331-B2

Title: Liquid crystal display

Description:
This application claims priority to Korean Patent Application No. 10-2015-0082131 filed on Jun. 10, 2015, and all the benefits accruing therefrom under 35 U.S.C. §119, the content of which in its entirety is herein incorporated by reference. 
     BACKGROUND 
     1. Field 
     The exemplary embodiments of the invention relate to a liquid crystal display (“LCD”). 
     2. Description of the Related Art 
     A liquid crystal display (“LCD”) is one of the most widely used flat panel displays. An LCD includes two panels provided with field-generating electrodes such as pixel electrodes and a common electrode and a liquid crystal layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field, which determines the orientation of liquid crystal molecules in the liquid crystal layer to adjust polarization of incident light. 
     One type of the LCD is a vertical alignment (“VA”)-mode LCD, which aligns liquid crystal molecules such that the longitudinal axes of the liquid crystal molecules are perpendicular to the panels in the absence of an electric field, is spotlighted because of its high contrast ratio and wide reference viewing angle. 
     The wide reference viewing angle of the VA-mode LCD can be realized by forming a plurality of domains that differ from one another in terms of the orientation of the liquid crystal molecules in one pixel. 
     To form the plurality of domains in one pixel, there has been suggested a method of forming cutouts such as minute slits in the field-generating electrodes or forming protrusions on the field-generating electrodes. In this method, the plurality of domains may be provided by realigning the liquid crystal molecules perpendicular with respect to fringe fields generated between edges of the cutouts or protrusions, and the field-generating electrodes facing the edges. 
     Examples of an LCD with means for forming domains include a VA-mode LCD in which means for forming domains is provided on both upper and lower panels and a patternless VA (“PVA”)-mode LCD in which minute patterns are disposed on a lower panel, but not on an upper panel. A display area is divided into a plurality of domains by the means for forming domains, and liquid crystal molecules in each of the domains are tilted mostly in the same direction. 
     The VA-mode LCD, which aligns liquid crystal molecules such that the long axes of the liquid crystal molecules are perpendicular to the panels in the absence of an electric field, is popular for its high contrast ratio and wide reference viewing angle, which is defined as a viewing angle making a contrast ratio equal to 1:10 or as a limit angle for the inversion of luminance between grayscale levels. 
     In the VA-mode LCD, the securing of a wide viewing angle is critical. The wide viewing angle of the VA mode LCD can be realized by forming cutouts such as minute slits in the field-generating electrodes or forming protrusions on the field-generating electrodes. The cutouts and the protrusions can determine the tilt direction of liquid crystal molecules, which can be distributed into varying directions to widen the reference viewing angle. 
     SUMMARY 
     A vertical alignment (“VA”)-mode liquid crystal display (“LCD”) has poor side visibility as compared with front visibility. To overcome the above described drawback, a method has been suggested in which a pixel electrode is divided into two sub-pixel electrodes and a high voltage and a low voltage are respectively applied to the two sub-pixel electrodes such that the orientation of liquid crystal molecules can vary from one sub-pixel electrode to another sub-pixel electrode, and that the visibility in a left-to-right viewing angle direction can be improved. 
     Exemplary embodiments of the invention provide an LCD with improved visibility and transmittance. 
     However, exemplary embodiments of the invention are not restricted to those set forth herein. The above and other exemplary embodiments of the invention will become more apparent to one of ordinary skill in the art to which the invention pertains by referencing the detailed description of the invention given below. 
     According to an exemplary embodiment of the invention, an LCD, comprising a first panel including a first electrode, which comprises side electrodes that are disposed in edge areas of a pixel, a central electrode that is connected to the side electrodes and is disposed in a central area of the pixel, and fine branches, some of which are connected to the side electrode, a second panel including a cutout, which corresponds to the first electrode and divides the fine branches, the central electrode and the side electrode into a plurality of domains, and a second electrode, which is separated by the cutout and corresponds to each of the domains, and a liquid crystal layer disposed between the first and second panels and including liquid crystal molecules, wherein the first panel further includes second slit patterns, which are provided by partially cutting out ends of the fine branches, separate the side electrodes and the fine branches from each other, and extend in parallel to a longitudinal direction of the side electrodes. 
     In an exemplary embodiment, the fine branches may be disposed in each of the domains and include a plurality of branch electrodes and the branch electrodes include first slit patterns, which are provided by removing parts of the pixel between the branch electrodes and separate the branch electrodes from one another. 
     In an exemplary embodiment, the branch electrodes and the first slit patterns in one of the domains may be asymmetrical to the branch electrodes and the first slit patterns in another one of the domains. 
     In an exemplary embodiment, the side electrodes may be disposed on at least one of the left and right sides and the top and the bottom sides of the pixel, and the second slit patterns, which separate the side electrodes and the fine branches from each other, are disposed in at least one of the domains. 
     In an exemplary embodiment, a width of the side electrodes and the second slit patterns may be in the range of about 7 micrometers (μm) to about 9 μm. 
     In an exemplary embodiment, a distance between the side electrodes and the branch electrodes may be in the range of about 3 μm to about 5 μm. 
     In an exemplary embodiment, a width of the second silt patterns may be in the range of about 3 μm to about 5 μm. 
     In an exemplary embodiment, the branch electrodes and the first slit patterns may be disposed at a pitch of about 6 μm to about 10 μm. 
     In an exemplary embodiment, a length to which the fine branches extend from one side of the central electrode to the pixel may be about 30 μm or less. 
     In an exemplary embodiment, the second slit patterns may be disposed between every other pair of branch electrodes. 
     In an exemplary embodiment, the central electrode may be provided in one of a polygonal shape, including the shapes of a cross, a rhombus, a rectangle, and an octagon, a circular shape and a combination thereof. 
     In an exemplary embodiment, the branch electrodes and the first slit patterns in one of the domains may be arranged in an alternate manner in a pair of adjacent domains. 
     In an exemplary embodiment, the second electrode may include a horizontal cutout portion, which horizontally divides the domains across the central electrode, and a vertical cutout portion, which intersects the horizontal cutout portion and vertically divides the domains across the central electrode. 
     In an exemplary embodiment, the first electrode is disposed between the central electrode and the side electrodes and further may include a connecting electrode, which is disposed in an area corresponding to the cutout. 
     In an exemplary embodiment, a width of the cutout may be in the range of about 2 μm to about 5 μm. 
     In an exemplary embodiment, the first electrode further may includes first areas in which parts of the fine branches adjacent to the central electrode are located and second areas which are apart from the central electrode and in which at least one of the side electrodes is disposed at the ends of at least one of the fine branches, and the second slit patterns are disposed near at least one of the second areas and rotate liquid crystal molecules in the second areas in a direction similar to a direction of an average azimuth angle of liquid crystal molecules in the first areas. 
     In an exemplary embodiment, a direction in which the branch electrodes extend may be the same as a direction of an average azimuth angle of the liquid crystal molecules. 
     In an exemplary embodiment, The LCD further comprising: first and second polarizing plates, which may be disposed on the first and second panels, respectively, wherein a direction in which the branch electrodes extend is in the range of angles of about 30 degrees (°) to about 60° relative to a polarization axis of the first and second polarizing plates. 
     In an exemplary embodiment, the second slit patterns may be arranged in an alternate manner in a pair of adjacent pixels. 
     In an exemplary embodiment, a width of the branch electrodes is the same as a width of the first silt patterns. 
     According to the exemplary embodiments, it is possible to improve the visibility and transmittance of an LCD by defining, in each pixel, slit patterns that define the shape of electrodes and separate the electrodes from one another. 
     Other features and exemplary embodiments will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other exemplary embodiments, advantages and features of this invention will become more apparent by describing in further detail exemplary embodiments thereof with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic plan view illustrating an exemplary embodiment of a pixel of a liquid crystal display (“LCD”) according to the invention. 
         FIG. 2  is a schematic cross-sectional view taken along line I-I′ of  FIG. 1 . 
         FIG. 3  is an enlarged plan view illustrating an example of a domain illustrated in  FIG. 1 . 
         FIG. 4  is an enlarged plan view illustrating another example of a domain illustrated in  FIG. 1 . 
         FIG. 5  is a diagram illustrating the behavior of liquid crystal molecules of the LCD of  FIG. 1 . 
         FIGS. 6 to 8  are images captured from the planes of exemplary embodiments of pixels of LCDs according to the invention and the plane of a pixel of an LCD according to a comparative example. 
         FIG. 9  is a graph showing an exemplary embodiment of the distribution of the azimuth angles of liquid crystal molecules in a pixel of an LCD according to the invention and in a pixel of an LCD according to a comparative example. 
         FIG. 10  is a graph showing an exemplary embodiment of the variation of the transmittance of a pixel with a voltage in an LCD according to the invention. 
         FIG. 11  is a graph showing an exemplary embodiment of the variation of the transmittance of a pixel with grayscale in an LCD according to the invention. 
         FIG. 12  is a graph showing an exemplary embodiment of the transmittance and visibility of an LCD according to the invention. 
         FIGS. 13 to 18  are plan views of to exemplary embodiments of pixels of LCDs according the invention. 
         FIG. 19  is an equivalent circuit diagram of an exemplary embodiment of a pixel of an LCD according to the invention. 
         FIG. 20  is a plan view of the pixel of the LCD of  FIG. 19 . 
         FIG. 21  is a cross-sectional view taken along line of  FIG. 20 . 
         FIG. 22  is a graph showing a gamma curve of the LCD of  FIG. 19 . 
     
    
    
     DETAILED DESCRIPTION 
     The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “comprises,” comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Various exemplary embodiments are described herein with reference to sectional illustrations that are schematic illustrations of idealized exemplary embodiments and/or intermediate structures. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments disclosed herein should not be construed as limited to the particular illustrated shapes of regions, but are to include deviations in shapes that result from, for instance, manufacturing. The regions illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to be limiting. 
     It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein. 
     Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element&#39;s relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. In an exemplary embodiment, when the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure. Similarly, when the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below. 
     “About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention is a part. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense, unless expressly so defined herein. 
     Exemplary embodiments of the invention will now be explained with reference to the drawings. 
       FIG. 1  is a schematic plan view illustrating a pixel of a liquid crystal display (“LCD”) according to an exemplary embodiment of the invention,  FIG. 2  is a schematic cross-sectional view taken along line I-I′ of  FIG. 1 ,  FIG. 3  is an enlarged plan view illustrating an example of a domain illustrated in  FIG. 1 ,  FIG. 4  is an enlarged plan view illustrating another example of the domain illustrated in  FIG. 1 , and  FIG. 5  is a diagram illustrating the behavior of liquid crystal molecules of the LCD of  FIG. 1 . 
       FIGS. 1 to 5  illustrate a pixel PX of the LCD according to the illustrated exemplary embodiment, but the LCD according to the illustrated exemplary embodiment may include a plurality of pixels, which are arranged in rows and columns. 
     Referring to  FIGS. 1 and 2 , an LCD  1  includes first and second panels  100  and  200 , which face each other, and a liquid crystal layer  300 , which is disposed between the first and second panels  100  and  200 . 
     The first panel  100  may include a first substrate  110 , a first electrode  191  and a first alignment layer  130 , which are sequentially disposed on one surface of the first substrate  110 , and a first polarizing plate  140 , which is disposed on the other surface of the first substrate  110 . In an exemplary embodiment, the first electrode  191  included in the first panel  100  may be, for example, a pixel electrode. 
     The second panel  200  may include a second substrate  210 , a second electrode  270  and a second alignment layer  230 , which are sequentially disposed on one surface of the second substrate  210 , and a second polarizing plate  240 , which is disposed on the other surface of the second substrate  210 . In an exemplary embodiment, the second electrode  270  included in the second panel  200  may be, for example, a common electrode. 
     In an exemplary embodiment, the pixel PX may have a substantially rectangular shape, for example. The pixel electrode  191  may be disposed to cover the pixel PX, and the common electrode  270  may be integrally disposed on the entire surface of the second panel  200 . A cutout  280  may be defined in part of the common electrode  270 , but the invention is not limited thereto. 
     The first panel  100  or the second panel  200  may also include a switching device (not illustrated), a color filter (not illustrated), and a light-shielding member (not illustrated). In an exemplary embodiment, one of the first and second polarizing plates  140  and  240  may be optional. In an exemplary embodiment, one or both of the first and second alignment layers  130  and  230  may be optional. 
     The liquid crystal layer  300  may include liquid crystal molecules with negative dielectric anisotropy or with positive dielectric anisotropy or liquid crystal molecules with positive dielectric anisotropy or with positive dielectric anisotropy. In the illustrated exemplary embodiment, the liquid crystal layer  300  may include liquid crystal molecules  302  with negative dielectric anisotropy, for example. The longitudinal axes of the liquid crystal molecules  302  of the liquid crystal layer  300  may be vertically aligned with respect to the surfaces of the alignment layers  130  and  230  in the absence of an electric field between the first and second electrodes  191  and  270 . In an alternative exemplary embodiment, the liquid crystal molecules  302  may be aligned to have a pretilt angle with respect to a direction of the thickness of the liquid crystal layer  300 . 
     In response to a potential difference being generated between the pixel electrode  191  and the common electrode  260  so as to generate an electric field in the liquid crystal layer  300 , the liquid crystal molecules  302  may be aligned such that their longitudinal axes may become perpendicular to the electric field. The degree of the polarization of light incident upon the liquid crystal layer  300  may vary according to the degree to which the liquid crystal molecules  302  are tilted, and variations in the polarization of the incident light may appear as variations in transmittance due to the first and second polarizing plates  140  and  240 , and as a result, the LCD  1  may display an image. 
     To improve the viewing angle of the LCD  1 , which displays an image, patterns may be provided on the pixel electrode  191  and the common electrode  270  so as to define a plurality of domains. 
     More specifically, the pixel PX may include the common electrode  270 , which corresponds to the pixel electrode  191 , and the cutout  280 , which may adjust the direction of an electric field, may be disposed on the common electrode  270  by cutting out a portion of the common electrode  270 . 
     Accordingly, by patterning the pixel electrode  191  and the common electrode  270 , the pixel PX may be divided into a plurality of domains where liquid crystal molecules  302  having different average azimuth angles are oriented in different directions. Liquid crystal molecules  302  having an average azimuth angle will hereinafter be referred to as an average azimuth angle  310 . 
     In an exemplary embodiment, the pixel PX may include four domains, which are defined by a horizontal cutout portion  283  and a vertical cutout portion  286  of the common electrode  270 , i.e., first to fourth domains Da to Dd. In an exemplary embodiment, the width of the cutout  280  may be about 2 micrometers (μm) to about 4.5 μm. When the width of the cutout  280  is about 2 μm to about 4.5 μm, the visibility of the LCD  1  may be improved without compromising the transmittance of the pixel PX. When the width of the cutout  280  is about 6 μm or larger, a fringe field may increase along the boundaries between the first and fourth domains Da and Dd and between the second and third domains Db and Dc, and as a result, the transmittance of the pixel PX may decrease. Also, the liquid crystal molecules  302  may not be sufficiently laid down in the area where the cutout  280  is provided, and as a result, the transmittance of the pixel PX may decrease. 
     Due to the horizontal and vertical cutouts  283  and  286  of the common electrode  270 , the pixel electrode  191  may be divided into the first to fourth domains Da to Dd. 
     The pixel electrode  191  may include, in each of the first to fourth domains Da to Dd, a side electrode  193 , which is disposed in an edge area of the pixel PX, a central electrode  192 , which is connected to the side electrode  193  and is disposed in a central area of the pixel PX, and fine branches  194 , which extend from at least one of the sides of the central electrode  192  in one direction and some of which are connected to the side electrode  193 . The fine branches  194  may include first branch electrodes  194   a , second branch electrodes  194   b , third branch electrodes  194   c , and fourth branch electrodes  194   d , which are disposed in the first, second, third, and fourth domains Da, Db, Dc, and Dd, respectively. 
     In each of the first to fourth domains Da to Dd, first slit patterns  195   a , which are provided by removing parts of the pixel PX between the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  to expose an insulating layer therebelow, and separate the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  from one another, and a second slit pattern  195   b , which separates at least one of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  from the side electrode  193  may be defined in the pixel PX. The second slit pattern  195   b  may be provided by partially removing an end portion of at least one of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c  or  194   d  to expose the insulating layer, which is disposed below the pixel electrode  191 . 
     The side electrode  193  and one of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c  or  194   d  may be connected to each other, and a connecting electrode  199  may be disposed at the boundary between the side electrode  193  and the central electrode  192  to overlap the horizontal and vertical cutouts  283  and  286 . Accordingly, the central electrode  192 , the fine branches  194  and the side electrode  193  of the pixel electrode  191  may be connected to one another. 
     The pixel electrode  191 , which is disposed in the pixel PX, may include the central electrode  192 , the fine branches  194 , and the side electrode  193 , and the central electrode  192 , and the fine branches  194 , and the side electrode  193  may be unitary and may thus receive the same voltage. The pixel electrode  191  may define a plurality of domains, i.e., the first to fourth domains Da to Dd, due to the horizontal and vertical cutouts  283  and  286 . 
     In an exemplary embodiment, the central electrode  192  may be in the shape of a rhombus, for example, but the invention is not limited thereto. That is, the central electrode  192  may be provided in the same shape as that of the horizontal and vertical cutouts  283  and  286 . The area of the central electrode  192  may vary, and the central electrode  192  may be provided to have a smaller area than that illustrated in  FIG. 1 . 
     The fine branches  194 , which extend from the sides of the central electrode  192 , may be disposed in the pixel PX. The fine branches  194  may include the first branch electrodes  194   a , the second branch electrodes  194   b , the third branch electrodes  194   c , and the fourth branch electrodes  194   d , which are disposed in the first, second, third, and fourth domains Da, Db, Dc, and Dd, respectively. The first branch electrodes  194   a , the second branch electrodes  194   b , the third branch electrodes  194   c , and the fourth branch electrodes  194   d  will hereinafter be collectively referred to as the fine branches  194 . 
     The first branch electrodes  194   a  may be disposed in the first domain Da and may diagonally extend from the horizontal or vertical cutout portion  283  or  286  in an upper right direction, and the second branch electrodes  194   b  may be disposed in the second domain Db and may diagonally extend from the horizontal or vertical cutout portion  283  or  286  in an upper left direction. The third branch electrodes  194   c  may be disposed in the third domain Dc and may diagonally extend from the horizontal or vertical cutout portion  283  or  286  in a lower left direction, and the fourth branch electrodes  194   d  may be disposed in the fourth domain Dd and may diagonally extend from the horizontal or vertical cutout portion  283  or  286  in a lower right direction. 
     In an exemplary embodiment, the first branch electrodes  194   a  and the second branch electrodes  194   b  may be disposed at an angle of about 45 degrees)(° or about 130° relative to the horizontal cutout portion  283 , for example. In an exemplary embodiment, the third branch electrodes  194   c  and the fourth branch electrodes  194   d  may be disposed at an angle of about 225° or about 315° relative to the horizontal cutout portion  283 , for example. Branch electrodes in one of a pair of adjacent domains may intersect branch electrodes in the other domain. 
     In response to the fine branches  194  extending from at least one of the sides of the central electrode  192  as described above, the control of the liquid crystal molecules  302  may be improved, texture may be reduced, and the transmittance and response speed of the LCD  1  may be improved. Particularly, the performance of the LCD  1  such as the control of the liquid crystal molecules  302  may be effectively improved when fine branches  194  corresponding to the edges of each sub-pixel electrode  191 H or  191 L (refer to  FIG. 20 ) extend asymmetrically with respect to fine branches  194  not corresponding to the edges of each sub-pixel electrode  191 H or  191 L, i.e., when the branch electrodes  194   a  to  194   d  are disposed such that the ends of the branch electrodes  194   a  to  194   d  correspond to the first slit patterns  195   a.    
     In each of the first to fourth domains Da to Dd, a second slit pattern  195   b , which separates the end of at least one of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  from the side electrode  193  may be defined in the pixel PX. 
     The first slit patterns  195   a  may be disposed in each of the first to fourth domains Da to Dd of the pixel PX and may define gaps among the branch electrodes  194  such that each pair of adjacent branch electrodes  194  is separated by a predetermined distance. The first slit patterns  195   a  may separate the branch electrodes  194  from one another, and the first slit patterns  195   a  and the branch electrodes  194  may be diagonally disposed with respect to the cutout  280 . Accordingly, the liquid crystal molecules  302  may be aligned to have the average liquid azimuth angle  310  that achieves maximum transmittance. 
     The second slit pattern  195   b  may be connected to some of the first slit patterns  195   a , and may be provided by removing end portions of at least some of the branch electrodes  194  near the side electrode  193 , and may separate the side electrode  193  and the branch electrodes  194  from each other. 
     The second slit pattern  195   b  may be provided in at least one of the first to fourth domains Da to Dd. In the illustrated exemplary embodiment, the second slit pattern  195   b  may be disposed in each of the first to fourth domains Da to Dd to extend in parallel to the side electrode  193 , but the invention is not limited thereto. 
     The second slit pattern  195   b , which is disposed in at least one of the first to fourth domains Da to Dd, may not be provided in the connecting electrode  199 , and may also not be provided between the side electrode  193  and at least some of the branch electrodes  194 . 
     That is, the second slit pattern  195   b  may not be provided in an area where the connecting electrode  199  is provided to connect the central electrode  192  and the side electrode  193  or to connect the side electrode  193  and some of the branch electrodes  194 , and may also not be provided between the side electrode  193  and at least some of the branch electrodes  194 . 
     In the illustrated exemplary embodiment, the second slit pattern  195   b  may be bar-shaped, for example, and may be disposed near the side electrode  193  to extend in parallel to the side electrode  193 , and the side electrode  193  and the branch electrodes  194  may be connected to each other at the corners of the pixel PX. Accordingly, the second slit pattern  195   b  may be provided throughout the entire pixel PX except for a corner area and the area where the connecting electrode  199  is provided. 
     In an alternative exemplary embodiment, the central electrode  192  and the branch electrodes  194  may be connected to each other and may also be connected to the side electrode  193  via the connecting electrode  199 . In this alternative exemplary embodiment, the second slit pattern  195   b  may be also disposed in a corner area of the pixel PX. 
     In an exemplary embodiment, the first slit patterns  195   a , the second slit pattern  195   b , and the branch electrodes  194  may have the same width. The side electrode  193  may have the same width as that of the branch electrodes  194 . Accordingly, the force of an electric field between the branch electrodes  194  may be similar to the force of an electric field between the side electrode  193  and the branch electrodes  194 , and thus, the liquid crystal molecules  302  may be prevented from being tilted in any particular direction. 
     In an exemplary embodiment, the branch electrodes  194  and the first slit patterns  195   a  may be disposed at a pitch of about 6 μm to about 10 μm, for example. More specifically, the branch electrodes  194  and the first slit patterns  195   a  may be disposed at a pitch of about 7 μm to about 9 μm, for example. In an exemplary embodiment, the side electrode  193  and the end portions of the branch electrodes  194  may have a width of about 7 μm to about 9 μm, for example. In an exemplary embodiment, the distance between the side electrode  193  and the branch electrodes  194 , i.e., the width of the second slit pattern  195   b , may be in the range of about 3 μm to about 5 μm, for example. 
     In an exemplary embodiment, the length of the branch electrodes  194 , i.e., i.e., the length to which the branch electrodes  194  extend from one side of the central electrode  192  to the pixel PX, may be about 30 μm or less, for example. 
     Assuming that liquid crystal molecules  302  having an average alignment direction, which is obtained by averaging the alignment directions of liquid crystal molecules  302  in the first, second, third, or fourth domain Da, Db, Dc, or Dd, are the average azimuth angle of an average alignment direction  310 , the average azimuth angle of an average alignment direction  310  may be tilted in a direction corresponding to the sum of the vector of an electric field generated in each of the first, second, third, or fourth domain Da, Db, Dc, or Dd due to an electric field and a vector provided by collisions between the liquid crystal molecules  302 . That is, the liquid crystal molecules  302  may define an azimuth angle similar to a direction in which the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  extend. In each of the first to fourth domains Da to Dd, the liquid crystal molecules  302  may be aligned to have an average azimuth angle  310  corresponding to a direction a, b, c, or d. 
     More specifically, the liquid crystal molecules  302  may be aligned almost in parallel to four diagonal directions from four corners of the pixel electrode  191  to the center of the cutout  280  of the common electrode  270 , which is cross-shaped. As a result, the directors of the liquid crystal molecules  302  may be aligned accordingly in each of the first to fourth domains Da to Dd, and the liquid crystal molecules  302  may be tilted in a total of four directions across regions of a field-generating electrode. 
     In each of the first to fourth domains Da to Dd, the liquid crystal molecules  302  may define an average azimuth angle  310  in a similar direction to the direction in which the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  extend. 
     Accordingly, since the branch electrodes  194  extend in a total of four directions within the pixel PX, the liquid crystal molecules  302  may be tilted in a total of four directions. By varying the direction in which the liquid crystal molecules  302  are tilted, the reference viewing angle of the LCD  1  may be widened. 
       FIG. 3  illustrates an exemplary embodiment in which the side electrode  193  is disposed on both sides of the pixel PX (refer to  FIG. 13 ), and  FIG. 4  illustrates an exemplary embodiment in which the side electrode  193  is disposed not only on both sides of the pixel, but also at the top and the bottom sides of the pixel PX.  FIG. 5  illustrates a peripheral area of the pixel PX to explain the behavior of liquid crystal molecules. 
     The LCD  1  may realize grayscale levels by applying voltages between the pixel electrode  191  and the common electrode  270  so as to change the behavior of the liquid crystal molecules and thus to vary the refractive index of the liquid crystal layer  300 . 
     The LCD  1  achieves a high contrast ratio due to its excellent “dark” properties, but may result in differences in liquid crystal transmittance depending on the behavior of the liquid crystal molecules  302  and the direction from which the LCD  1  is viewed because the LCD  1  uses liquid crystal molecules  302  with negative dielectric anisotropy. That is, the LCD  1  may have weaknesses in its viewing angle because the transmittance of the LCD  1  varies from one direction to another direction. 
     In order to address this viewing angle issue, an electrode pattern may be disposed on both the first panel  100  and the second panel  200 , as described above with reference to  FIGS. 1 and 2 , so as to define a multi-domain region that changes the direction of the behavior of the liquid crystal molecules  302 . The electrode pattern may be the pixel electrode  191  (refer to  FIG. 20 ) or the common electrode  270 . 
     By defining a plurality of domains, e.g., the first to fourth domains Da to Dd, differences in the refractive index of the liquid crystal layer  300  from one viewing angle direction to another viewing angle direction may be minimized, and thus, visibility may be improved. Differences in the refractive index of the liquid crystal layer  300  from one viewing angle direction to another viewing angle direction may be minimized by using the first to fourth domains Da to Dd, but the problem of the distortion of a grayscale curve on the sides of the pixel PX may arise. 
     More specifically, in the multi-domain structure including the first to fourth domains Da to Dd, disclination lines may be generated on the sides of the pixel PX because some liquid crystal molecules  302  are moved in a direction corresponding to the polarization axis of the polarizing plates  140  and  240  during a “bright” or “dark” state. As a result, the optical efficiency of the LCD  1  may decrease. 
     To overcome the problem associated with disclination lines, the electrode patterns  191  and  270  may be varied, as described above with reference to  FIGS. 1 and 2 , so as to reduce the distortion of a grayscale curve in a low-grayscale period (or a “dark” state) and a high-grayscale period (or a “bright” state). Also, differences in transmittance between the high-grayscale period and the low-grayscale period may be reduced so as to minimize the distortion of a grayscale curve and thus to improve visibility and thus to improve visibility. 
     The behavior of liquid crystal molecules for minimizing the distortion of a gamma curve will hereinafter be described with reference to  FIGS. 3 to 5 , taking a domain as an example. 
     Referring to  FIGS. 3 to 5 , an electric field may be generated in the liquid crystal layer  300  between two field-generating electrodes, i.e., the pixel electrode  191  and the common electrode  270 , by applying a data voltage to the pixel electrode  191  and applying a common voltage to the common electrode  270 . 
     Fringe fields F 1  to F 4  may be generated in the liquid crystal layer  300  in response to an electric field being generated in the liquid crystal layer  300 . A horizontal electric field in a first direction, a horizontal electric field in a second direction, a horizontal electric field in a third direction, and a horizontal electric field in a fourth direction will hereinafter be referred to as a first horizontal electric field F 1 , a second horizontal electric field F 2 , a third horizontal electric field F 3 , and a fourth horizontal electric field F 4 , respectively. 
     First directors  301   a  and second directors  301   b , which are oriented in a direction from two sides of the pixel electrode  191  to the inside of the pixel PX due to the first and second horizontal electric fields F 1  and F 2 , and third directors  301   c  and fourth directors  301   d , which are oriented from the cutout  280  of the common electrode  270  to the inside of the pixel PX due to the third and fourth horizontal electric fields F 3  and F 4 , may be tilted substantially in parallel to the polarization axis of the polarizing plates  140  and  240 . That is, the liquid crystal molecules  302  may be tilted in a total of four directions in a single domain of the pixel PX. 
     More specifically, in an area along the edges of the pixel electrode  191  in the pixel PX, the first directors  301   a  and the second directors  301   b  may be perpendicular to the corresponding edges of the pixel electrode  191 . In an area near the cutout  280  of the common electrode  270  in the pixel PX, the third directors  301   c  and the fourth directors  301   d  may be perpendicular to the corresponding edges of the cutout  280  of the common electrode  270 . 
     As mentioned above, due to the fringe fields F 1  to F 4  generated by the edges of the pixel electrode  191  and the cutout  280  of the common electrode  270 , the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d  may be defined. 
     The liquid crystal molecules  302  may be primarily aligned almost in parallel to the polarization axis of the polarizing plates  140  and  240  due to the fringe fields F 1  to F 4  generated by the pixel electrode  191  and the common electrode  270 , thereby providing the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d . The liquid crystal molecules  302  primarily aligned according to the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d  may be secondarily aligned so as to minimize distortion in the pixel PX. The direction in which the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d  are secondarily aligned may be a direction corresponding to the sum of the vectors of the directions of the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d.    
     Accordingly, the direction in which the liquid crystal molecules  302  are secondarily aligned, i.e., the direction corresponding to the sum of the vectors of the directions of the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d , may be similar to the direction in which the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  in the first, second, third, or third domain Da, Db, Dc, or Dd extend, and the average azimuth angle  310  may be provided in a direction similar to the direction in which the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  in the first, second, third, or third domain Da, Db, Dc, or Dd extend. That is, the liquid crystal molecules  302  may be aligned to have different average azimuth angles  310  in different domains of the pixel PX. 
     The first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d  may be provided in the first slit patterns  195   a  between the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d.    
     More specifically, the sides of each of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  may distort an electric field, thereby generating horizontal components that are perpendicular to the sides of each of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d , and a direction in which the liquid crystal molecules  302  are to be tilted may be determined by the fringe fields F 1  to F 4 . Accordingly, the liquid crystal molecules  302  may initially tend to be tilted in a direction perpendicular to the sides of each of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d.    
     Since the directions of horizontal components of an electric field generated by the sides of a pair of adjacent first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  are opposite to each other and the gap between the pair of adjacent first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  is narrow, liquid crystal molecules  302  that tend to be tilted in opposite directions may all be tilted in a direction parallel to the longitudinal direction of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d.    
     Accordingly, in the illustrated exemplary embodiment, the liquid crystal molecules  302  may be tilted in the longitudinal direction of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  over two stages. In an alternative exemplary embodiment, the liquid crystal molecules  302  may be pretilted in the direction parallel to the longitudinal direction of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d  by providing protrusions on a substrate. 
     In the illustrated exemplary embodiment, the first slit patterns  195   a  may be defined in the pixel PX, and as a result, the liquid crystal molecules  302  may be tilted in the directions of the first directors  301   a , the second directors  301   b , the third directors  301   c , and the fourth directors  301   d  due to the fringe fields F 1  to F 4 . Accordingly, the response speed of the LCD  1  may be improved. 
     Due to the aforementioned behavior of the liquid crystal molecules  302 , different average azimuth angles  310  may be provided in different domains of the pixel PX. Referring back to  FIGS. 1 and 2 , in the first domain Da of the pixel PX, the directors of the liquid crystal molecules  302  may be diagonally aligned in an upper right direction relative to the horizontal cutout portion  283 , thereby defining an average azimuth angle  310  corresponding to the direction a. 
     In the second domain Db of the pixel PX, the directors of the liquid crystal molecules  302  may be diagonally aligned in an upper left direction relative to the horizontal cutout portion  283 , thereby defining an average azimuth angle  310  corresponding to the direction b. 
     In the third domain Dc of the pixel PX, the directors of the liquid crystal molecules  302  may be diagonally aligned in a lower left direction relative to the horizontal cutout portion  283 , thereby defining an average azimuth angle  310  corresponding to the direction c. 
     In the fourth domain Dd of the pixel PX, the directors of the liquid crystal molecules  302  may be diagonally aligned in a lower right direction relative to the horizontal cutout portion  283 , thereby defining an average azimuth angle  310  corresponding to the direction d. 
     Accordingly, the liquid crystal molecules  302  may be controlled to be aligned in different directions in different domains of the pixel PX along the longitudinal directions of the branch electrodes  194 , and thus, the side visibility of the LCD  1  may be improved. 
     In an area where the cutout  280  is defined, the intensity of the fringe fields F 1  to F 4 , which are applied to the pixel electrode  191 , may be adjusted by adjusting the width of the cutout  280 . In the area where the cutout  280  is defined, the fringe fields F 1  to F 4  may not be generated. 
     Referring back to  FIG. 3 , in one of the first to fourth domains Da to Dd, for example, in the first domain Da, an area where the central electrode  192  and parts of the fine branches  194  adjacent to the central electrode  192  are located may be defined as a first area X. In the first area X, the liquid crystal molecules  302  may be aligned mostly in a direction of the average azimuth angle  310  along the direction in which the first branch electrodes  194   a  extend, due to the force of the fringe fields F 1  to F 4  and collisions between the liquid crystal molecules  302 . 
     An area which is apart from the central electrode  192  and in which a side (e.g., a top side) of the pixel electrode  191  that is parallel to the horizontal cutout portion  283  is located may be defined as a second area Y, and an area where a side (e.g., a right side) of the pixel electrode  191  that is parallel to the vertical cutout portion  286  is located may be defined as a third area Z. In  FIG. 3 , an area where a side electrode  193  and a second slit pattern  195   b  of the pixel electrode  191  are provided may be defined as the third area Z, and an area where the side electrode  193  and the second slit pattern  195   b  of the pixel electrode  191  are not provided may be defined as the second area Y. 
     In the second area Y, only the force of the first horizontal electric field F 1 , which is generated along an edge of the pixel PX, may exist. That is, in the second area Y, liquid crystal molecules  302  having the first directors  301   a  may exist. Since the second area Y is relatively distant from the horizontal cutout portion  283 , the force of the third horizontal electric field F 3  may not reach the second area Y. Accordingly, since in the second area Y, a vector for secondarily moving the liquid crystal molecules  302  having the first directors  301   a , i.e., the third directors  301   c  provided by the force of the third horizontal electric field F 3 , rarely exist, the liquid crystal molecules  302  may be tilted in parallel to the vertical cutout portion  286 . 
     Thus, the first directors  301   a , which are substantially parallel to the polarization axis of the polarizing plates  140  and  240 , among other liquid crystal molecules  302  moved by the fringe fields F 1  to F 4 , may be disposed in the second area Y. 
     In an exemplary embodiment, the LCD  1  may achieve maximum transmittance only when the average azimuth angle  310  and the polarization axis of the polarizing plates  140  and  240  have an angle of about 45° therebetween in response to voltages being applied to the first and second panels  100  and  200 , for example. 
     However, since the horizontal and vertical edges of the pixel electrodes  191  and the horizontal and vertical cutouts  283  and  286  may be aligned with the polarization axis of the polarizing plates  140  and  240 , the transmittance of the LCD  1  may decrease in the second area Y because of the liquid crystal molecules  302  tilted in a similar direction to the direction of the polarization axis of the polarizing plates  140  and  240 . That is, in the second area Y, the angle between the average azimuth angle  310  and the polarization axis of the polarizing plates  140  and  240  may be less than about 45°, and as a result, the transmittance of the LCD  1  may decrease. 
     In the third area Z, since the second slit pattern  195   b  is disposed between the side electrode  193  and some of the first branch electrodes  194   a , a fringe field may be further generated in the side electrode  193  and the ends of the first branch electrodes  194   a . Thus, in an area where the second slit pattern  195   b  is defined, the liquid crystal molecules  302  collide with one another due to the fringe field. Accordingly, in the third area Z, the liquid crystal molecules  302  may be aligned in a similar direction to the direction of the average azimuth angle  310 . 
     More specifically, in a part of the third area Z where the connecting electrode  199  is provided, horizontal electric field components having the direction of the third directors  301   c , which are disposed in the side electrode  193 , and horizontal electric field components having the direction of the second directors  301   b , which are disposed at the lower ends of the first branch electrodes  194   a , may move the liquid crystal molecules  302 . 
     In part of the third area Z that is adjacent to the cutout  280 , the vectors of the second horizontal electric field F 2  and the third horizontal electric field F 3 , which move the liquid crystal molecules  302  in the directions of the third directors  301   c  and the second directors  301   b , may move the liquid crystal molecules  302  from an acute angle to an obtuse angle, thereby lowering the transmittance of the LCD  1 . 
     To address this problem, the LCD  1  may include the second slit pattern  195   b  in the pixel PX. 
     Referring to  FIG. 5 , a fringe field may be generated in the second slit pattern  195   b , i.e., between the side electrode  193  and the ends of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d . As a result, a sixth horizontal electric field F 6  may be generated in a direction to the ends of the first, second, third, or fourth branch electrodes  194   a ,  194   b ,  194   c , or  194   d , and a fifth horizontal electric field F 5  may be generated in a direction to the side electrode  193 . 
     In the third area Z where the side electrode  193  is provided, not only the fifth horizontal electric field F 5 , which is generated by a side of the pixel electrode  191 , but also the third horizontal electric field F 3 , which is generated by a side of the cutout  280  near the pixel electrode  191 , may serve as main horizontal electric fields. 
     In an area near the vertical cutout portion  286 , the fourth horizontal electric field F 4  may be generated. Since the fourth horizontal electric field F 4  is relatively distant from the third area Z, the third area Z may not be much influenced by the fourth horizontal electric field F 4 . The fifth horizontal electric field F 5  may be generated by a left side of the side electrode  193 , and may be in an opposite direction to a direction from outside toward a side of the pixel electrode  191 , i.e., the second horizontal electric field F 2 . 
     There may exist a vector for secondarily aligning the liquid crystal molecules  302  due to the collisions between “3-1” directors  301   c ′ and the fourth directors  301   d , which are moved by the fifth horizontal electric field F 5  and the third horizontal electric field F 3 . Accordingly, in the third area Z, liquid crystal molecules  302  moved with the “3-1” directors  301   c ′ and the third directors  301   c  may collide with one another and may thus be aligned to have a similar azimuth angle to the average azimuth angle  310 . The intensity of the fifth horizontal electric field F 5  along the edges of the pixel PX may vary depending on the distance to the cutout  280  and the width of the second slit pattern  195   b . In an exemplary embodiment, the width of the cutout  280  may be about 2 μm to about 5 μm. 
     In the third area Z on a side of the pixel PX, a fringe field capable of secondarily aligning the liquid crystal molecules  302  may be generated, and the liquid crystal molecules  302  may be aligned substantially in an average alignment direction of the first domain Da, i.e., in the direction of the average azimuth angle  310  of the first domain Da. Accordingly, any decrease in the transmittance of the LCD  1  that may be caused by irregular alignment of the liquid crystal molecules  302  along the sides of the pixel PX may be reduced. 
     In the illustrated exemplary embodiment, since the second slit pattern  195   b  may be disposed on a side of the first domain Da, the liquid crystal molecules  302  aligned in a similar direction to the direction of the polarization axis of the polarizing plates  140  and  240  may be adjusted to have the average azimuth angle  310 . Accordingly, the transmittance and the side viewing angle in the third area Z may be improved. In the illustrated exemplary embodiment, the second slit pattern  195   b  may be disposed only on both lateral sides of the pixel PX to improve the side viewing angle of the LCD  1 . 
     Accordingly, by defining the second slit pattern  195   b  in the pixel electrode  191 , the liquid crystal molecules  302  moved in the direction of the polarization axis of the polarizing plates  140  and  240  may be minimized, and as a result, the transmittance of the LCD  1  may be improved. 
     As illustrated in  FIG. 4 , in the first area X, the liquid crystal molecules  302  may be moved by the influence of fringe fields, and may collide with one another in the directions where they are moved. The liquid crystal molecules  302  may be moved in a direction parallel to the direction in which the first branch electrodes  194   a  extend. In an exemplary embodiment, the liquid crystal molecules  302  and the first branch electrodes  194   a  may be tilted about 45° with reference to the horizontal cutouts  283 . 
     The second slit pattern  195   b  may be disposed in both the second and third areas Y and Z, thereby generating a fringe field between the side electrode  193  and the ends of the first branch electrodes  194   a.    
     That is, in the second and third areas X and Y, the liquid crystal molecules  302  may collide with one another due to a fringe field, and may thus be aligned in a similar direction to the direction of the average azimuth angle  310 . The second slit pattern  195   b  may be disposed in the second and third areas Y and Z where the liquid crystal molecules  302  are not properly controlled and are thus aligned to have a similar azimuth angle to the polarization axis of the polarizing plates  140  and  240 . 
     The azimuth angle of the liquid crystal molecules  302  may be determined by the sum of a vector provided by an electric field and a vector provided by collisions between the liquid crystal molecules  302 . In order to generate force for moving the liquid crystal molecules  302 , the pixel electrode  191  and the common electrode  270  may be patterned in the pixel PX so as to control the azimuth angle of the liquid crystal molecules  302 . 
     The pixel electrode  191  and the common electrode  270  may be patterned in the pixel PX so as to generate an electric field in the liquid crystal layer  300  and thus to control the azimuth angle of the liquid crystal molecules  302 . As a result, liquid crystal molecules  302  having similar the average azimuth angle of an average alignment direction  310  may be obtained. Accordingly, the viewing angle of the LCD  1  may be improved. 
     Thus, a vector for secondarily aligning the liquid crystal molecules  302  along the sides of the pixel electrode  191  may be generated, and as a result, the liquid crystal molecules  302  near the edges of the pixel electrode  191  may be prevented from being tilted in a direction perpendicular to the sides of the pixel electrode  191 . That is, the degradation of the display quality of the LCD  1  that may be caused due to the liquid crystal molecules  302  near the edges of the pixel electrode  191 , i.e., the liquid crystal molecules  302  in the second or third area Y or Z, being aligned in parallel to the polarization axis of the polarizing plates  140  and  240  may be prevented. 
     In conclusion, by defining the second slit pattern  195   b  in the pixel electrode  191 , the liquid crystal molecules  302  moved in the direction of the polarization axis of the polarizing plates  140  and  240  may be minimized, and as a result, the transmittance of the LCD  1  may be improved. 
       FIGS. 6 to 8  are images captured from the planes of pixels of LCDs according to exemplary embodiments of the invention and the plane of a pixel of an LCD according to a comparative example,  FIG. 9  is a graph showing the distribution of the azimuth angles of liquid crystal molecules in a pixel of an LCD according to an exemplary embodiment of the invention and in a pixel of an LCD according to a comparative example,  FIG. 10  is a graph showing the variation of the transmittance of a pixel with a voltage in an LCD according to an exemplary embodiment of the invention,  FIG. 11  is a graph showing the variation of the transmittance of a pixel with grayscale in an LCD according to an exemplary embodiment of the invention, and  FIG. 12  is a graph showing the transmittance and visibility of an LCD according to an exemplary embodiment of the invention. 
     In the description that follows,  FIGS. 1 to 5  will be referred to again for convenience. 
       FIG. 6  shows an image captured from a pixel of a related-art LCD, and  FIGS. 7 and 8  show images captured from pixels of LCDs according to embodiments 1 and 2 of the invention. More specifically,  FIG. 7  shows an image captured from a pixel PX with a second slit pattern  195   b  disposed on both sides thereof, and  FIG. 8  shows an image captured from a pixel PX with a second slit pattern  195   b  disposed at the top and bottom sides thereof.  FIG. 9  shows the distribution of the azimuth angles of liquid crystal molecules in a plane along line II-II′ of  FIG. 1 . 
     Referring to  FIGS. 6 to 9 , an LCD  1  includes second slit patterns  195   b , which separate side electrodes  193  and branch electrodes  194  from each other and are disposed in parallel to the side electrodes  193 . The following description will be presented, taking the third area Z as an example. 
     When liquid crystal molecules  302  having first directors  301   a , second directors  301   b , third directors  301   c , and fourth directors  301   d  that are moved by fringe fields are aligned in parallel to the polarization axis of polarizing plates  140  and  240 , the transmittance of the LCD  1  may be lowered. The liquid crystal molecules  302  disposed on the second slit patterns  195   b  may be adjusted by the second slit patterns  195   b  to have an average azimuth angle  310 . 
     In the related-art LCD of  FIG. 6 , no second slit patterns  195   b  are provided on the sides of the pixel PX. Thus, the force of the fourth horizontal electric field F 4  may be relatively apart from the third area and thus may not sufficiently reach the third area Z, and as a result, the third horizontal electric field F 3  and the second horizontal electric field F 2  may serve as main electric fields. Accordingly, in the related-art LCD, the liquid crystal molecules  302  may be aligned to have a different azimuth angle from the average azimuth angle  310  due to the sum of the vectors of the third horizontal electric field F 3  and the second horizontal electric field F 2 . 
     Due to the third horizontal electric field F 3  and the second horizontal electric field F 2 , the liquid crystal molecules  302  in the third area Z may be aligned in a direction similar to the polarization axis of the polarizing plates  140  and  240 , and as a result, the transmittance of the related-art LCD may decrease. 
     In the LCDs of  FIGS. 7 and 8 , the fifth horizontal electric field F 5  may be provided due to the second slit pattern  195   b , and due to the fifth horizontal electric field F 5 , the liquid crystal molecules  302  in the third area Z may be aligned to have a similar azimuth angle to the average azimuth angle  310 . Accordingly, the transmittance of the LCDs of  FIGS. 7 and 8  may be improved in the second area Y or the third area Z, i.e., on the sides of the pixel PX or at the top and the bottom sides of the pixel PX. 
     As illustrated in  FIG. 9 , when a low voltage is applied to the pixel electrode  191  to realize a low grayscale level in the pixel PX, the liquid crystal molecules  302  are aligned to have an azimuth angle of about 40°, and when a high grayscale level is realized, the liquid crystal molecules  302  are aligned to have an azimuth angle of about 60°.  FIG. 9  shows azimuth angle measurements obtained from the liquid crystal molecules  302  along the plane along line II-II′ of  FIG. 1  by applying a voltage of about 3.2 volts (V) and a voltage of about 4.2 V to the pixel electrode  191  to realize a low grayscale level and a high grayscale level, respectively. 
     Due to the second slit pattern  195   b , horizontal electric field components may be generated in the edges of the pixel PX, i.e., the second area Y or the third area Z, and thus, the liquid crystal molecules  302  may be adjusted to have the average azimuth angle  310 . 
     Referring to  FIG. 10 , at a high grayscale level, the LCD  1  has a similar front transmittance to the related-art LCD and a higher lateral transmittance than the related-art LCD, which is believed to be due to the presence of the second slit pattern  195   b.    
     At an intermediate or high grayscale level for which a voltage of about 4.2 V is applied, the difference between the front transmittance and the lateral transmittance of the LCD  1  may be reduced. Accordingly, an improvement in the visibility of the LCD  1  at an intermediate or high grayscale level may be expected. 
       FIG. 11  illustrates the variation of lateral transmittance with grayscale in each of the pixels of  FIGS. 6 to 8 . Referring to  FIG. 11 , embodiment 1 corresponds to a pixel PX with a second slit pattern  195   b  disposed on both sides thereof, i.e., the pixel PX of  FIG. 7 , and embodiment 2 corresponds to a pixel with a second slit pattern  195   b  disposed at the top and bottom sides thereof, i.e., the pixel PX of  FIG. 8 . 
     As illustrated in  FIG. 11 , a pixel PX with a second silt pattern  195   b  disposed on both sides thereof, i.e., the pixel PX according to embodiment 1, has a slightly higher transmittance than the pixel of the related-art LCD. The pixel PX according to embodiment 1 has an increased difference between the lateral transmittance and the front transmittance thereof, and has a visibility of about 0.294. 
     A pixel PX with a second slit pattern  195   b  at the top and bottom sides thereof, i.e., the pixel PX according to embodiment 2, has a lower transmittance than the pixel of the related-art LCD. The pixel PX according to embodiment 1 has a reduced difference between the lateral transmittance and the front transmittance thereof, and has a visibility of about 0.302. 
     In the exemplary embodiment of  FIG. 1  and other exemplary embodiments, the difference between the front transmittance and the lateral transmittance of the LCD  1  may be reduced, and as a result, the side visibility of the LCD  1  may be improved. The improvement of the visibility of the LCD  1  may be apparent when the second slit pattern  195   b  is disposed on both sides of the pixel PX. 
     Accordingly, the results of the measurement of lateral transmittance at different grayscale levels show that the LCD  1  exhibits an improvement of up to 0.006 in visibility, compared to the related-art LCD. 
       FIG. 12  shows transmittance and visibility measurements obtained from a pixel PX with a second slit pattern  195   b  disposed on both sides thereof, i.e., the pixel PX according to embodiment 1 and a pixel PX with a second slit pattern  195   b  disposed at the top and bottom sides thereof, i.e., the pixel PX according to embodiment 2, assuming that the transmittance of a pixel of the related-art LCD is 100% 
     Referring to  FIG. 12 , the pixel of the related-art LCD has a transmittance of 100% and a visibility of about 0.300, whereas the pixel PX according to embodiment 2 has a transmittance of about 101.8% and a visibility of about 0.302. That is, the pixel PX according to embodiment 2 has an increase of about 1.8% in transmittance and an increase of 0.002 in visibility, compared to the pixel of the related-art LCD. That is, the visibility of the pixel PX according to embodiment 2 is improved, compared to the pixel of the related-art LCD. 
     The pixel PX according to embodiment 1 has a transmittance of 102.0% and a visibility of about 0.294. That is, the pixel PX according to embodiment 1 has an increase of about 2% in transmittance and a decrease of 0.006 in visibility, compared to the pixel of the related-art LCD. That is, the visibility of the pixel PX according to embodiment 1 is generally improved, compared to the pixel of the related-art LCD. 
       FIGS. 13 to 18  are plan views of pixels of LCDs according to exemplary embodiments of the invention. In  FIGS. 1 to 5 and 13 to 18 , like reference numerals indicate like elements, and thus, descriptions thereof will be omitted or at least simplified. 
     A pixel electrode  191  of an LCD  1  according to another exemplary embodiment of the invention will hereinafter be described. The pixel electrode  191  may include a central pattern  192 , which is disposed in a central part of a pixel PX, and fine branches  194 , which extend from the sides of the central part  192 . The fine branches  194  may include a plurality of branch electrodes, i.e., first branch electrodes  194   a , second branch electrodes  194   b , third branch electrodes  194   c , and fourth branch electrodes  194   d , and first slit patterns  195   a , which correspond to gaps between the first branch electrodes  194   a , between the second branch electrodes  194   b , between the third branch electrodes  194   c , and between the fourth branch electrodes  194   d  that expose therethrough an insulating layer including a protective layer, may be provided in the pixel PX. 
     The pixel electrode  191  of the pixel PX may also include side electrodes  193 , which are disposed on both sides of the pixel electrode  191 . The central pattern  192 , the branch electrodes  194 , and the side electrodes  193  of the pixel electrode  191  are connected to one another. 
     Second slit patterns  195 - 1   b , which separate the ends of some of the branch electrodes  194  from the side electrodes  193  and extend in parallel to the longitudinal direction of the side electrodes  193 , may also be provided in the pixel PX. 
     More specifically, referring to  FIGS. 13 and 14 , second slit patterns  195 - 1   b , which are disposed along the longitudinal direction of the side electrodes  193  and are dot-shaped, may be provided. The second slit patterns  195 - 1   b  may be provided on both sides of the pixel electrode  191 , as illustrated in  FIGS. 13 and 14 , or may be provided at the top and the bottom sides of the pixel electrode  191 . 
     The second slit patterns  195 - 1   b  may connect the ends of some of the first slit patterns  195   a . When the second slit patterns  195 - 1   b  are provided at the ends of all the branch electrodes  194 , the pixel electrode  191  may have the same shape as that illustrated in  FIG. 1 . Instead, in the illustrated exemplary embodiment, a dot-shaped second slit pattern  195 - 1   b  may be provided between every other pair of first slit patterns  195   a . That is, the dot-shaped second silt pattern  195 - 1   b  may be provided at the ends of every other pair of first slit patterns  195   a  in a “stepping stone” manner. The branch electrodes  194  and the side electrodes  193  may be connected to each other in areas where the second slit patterns  195   b - 1  are not provided. 
     According to the illustrated exemplary embodiment, a vector for secondarily aligning liquid crystal molecules  302  near the edges of the pixel electrode  191  may be generated, thereby adjusting the tilt of the liquid crystal molecules  302  in directions perpendicular to the edges of the pixel electrodes  191 . That is, the degradation of the display quality of the LCD  1  that may be caused due to the liquid crystal molecules  302  in a third area Z (refer to  FIG. 3 ) on a side of the pixel PX being aligned in parallel to the polarization axis of polarizing plates  140  and  240  may be prevented. 
     By arranging the second slit patterns  195   b  on the sides of the pixel PX, the side visibility of the LCD may be improved. 
     As illustrated in  FIG. 14 , the second slit patterns  195 - 1   b  may be arranged in an alternate manner in a pair of adjacent pixels PX. 
     Gap portions  196  may be disposed among a plurality of pixels PX. The gap portions  196  may include horizontal gap portions  196   a , which horizontally separate the plurality of pixels PX from one another, and vertical gap portions  196   b , which vertically separate the plurality of pixels PX from one another. In the gap portions  196 , an insulating layer that exposes a protective layer separating the plurality of pixels PX from one another may be disposed. In areas where the gap portions  196  are provided, thin-film transistor (“TFT”) conductive lines, which control the plurality of pixels PX, may be disposed, and protrusions, which provide the liquid crystal molecules  302  with a pretilt angle, may also be disposed. 
     Due to horizontal electric field components generated by the second slit patterns  195 - 1   b , which are dot-shaped and may be provided along the boundaries between the plurality of pixels PX, the number of liquid crystal molecules  302  aligned in a 45° direction that maximizes transmittance and having an average azimuth angle  310  may be increased. 
     Referring to  FIGS. 15 and 16 , two second slit patterns  195   b , which are bar-shaped, may be disposed on both sides of a pixel PX. In the illustrated exemplary embodiment, side electrodes  193  may be disposed along all the edges of the pixel PX, i.e., at the top and bottom sides and on the left and right sides of the pixel PX. 
     For a proper distinction, the side electrodes  193  may be divided into first to fourth side electrodes  193   a  to  193   d , which are disposed at the top side, the bottom side, on the left side, and on the right side, respectively, of the pixel PX. More specifically, the side electrode  193  at the top of the pixel PX may be defined as the first side electrode  193   a , the side electrode  193  at the bottom of the pixel PX may be defined as the second side electrode  193   b , the side electrode  193  on the left side of the pixel PX may be defined as the third side electrode  193   c , and the side electrode  193  on the right side of the pixel PX may be defined as the fourth side electrode  193   d.    
     In the illustrated exemplary embodiment, a “2-1” slit pattern  195   b - 1  may be disposed near the fourth side electrode  193   d , which is provided in a first domain Da of the pixel PX, to extend in parallel to the fourth side electrode  193   d . The “2-1” slit pattern  195   b - 1  may be disposed on the right side of the first domain Da. That is, the “2-1” slit pattern  195   b - 1  may be provided near the fourth side electrode  193   d  as a bar extending in parallel to the longitudinal direction of the fourth side electrode  193   d.    
     A “2-2” slit pattern  195   b - 2  may be disposed near the first side electrode  193   a , which is provided in a second domain Db of the pixel PX, to extend in parallel to the first side electrode  193   a . The “2-2” slit pattern  195   b - 2  may be disposed at the left top side of the second domain Db. That is, the “2-2” slit pattern  195   b - 2  may be provided near the first side electrode  193   a  as a bar extending in parallel to the longitudinal direction of the first side electrode  193   a.    
     A “2-3” slit pattern  195   b - 3  may be disposed near the third side electrode  193   c , which is provided in a third domain Dc of the pixel PX, to extend in parallel to the third side electrode  193   c . The “2-3” slit pattern  195   b - 3  may be disposed on the left side of the third domain Dc. That is, the “2-3” slit pattern  195   b - 3  may be provided near the third side electrode  193   c  as a bar extending in parallel to the longitudinal direction of the third side electrode  193   c.    
     A “2-4” slit pattern  195   b - 4  may be disposed near the second side electrode  193   b , which is provided in a fourth domain Dd of the pixel PX, to extend in parallel to the second side electrode  193   b . The “2-4” slit pattern  195   b - 4  may be disposed at the right bottom of the fourth domain Dd. That is, the “2-4” slit pattern  195   b - 4  may be provided near the second side electrode  193   b  as a bar extending in parallel to the longitudinal direction of the second side electrode  193   b.    
     As illustrated in  FIGS. 15 and 16 , in response to a plurality of pixels PX being provided, a third side electrode  193   c  of one of the plurality of pixels PX and a fourth side electrode  193   d  of another one of the plurality of pixels PX may be disposed adjacent to each other. For convenience, it is assumed that there are four pixels PX provided, and that the upper right pixel PX, the upper left pixel PX, the lower left pixel PX, and the lower right pixel PX are defined as a first pixel PX 1 , a second pixel PX 2 , a third pixel PX 3 , and a fourth pixel PX 4 , respectively. The first to fourth pixels PX 1  to PX 4  may be separated from one another by a predetermined distance due to the presence of a vertical gap portion  196   b  and a horizontal gap portion  196   a.    
     A third domain Dc of the first pixel PX 1  may be disposed adjacent to a fourth domain Dd of the second pixel PX 2  in a horizontal direction. A second domain Db of the first pixel PX 1  may be disposed adjacent to a first domain Da of the second pixel PX 2  in a vertical direction. A “2-3” silt pattern  195   b - 3  in the third domain Dc of the first pixel PX 1  may be in an alternate arrangement with a “2-4” slit pattern  195   b - 4  in the fourth domain Dd of the second pixel PX 2 . 
     Accordingly, the “2-3” silt pattern  195   b - 3  in the third domain Dc of the first pixel PX 1  may generate horizontal electric field components in a border area with the fourth domain Dd of the second pixel PX 2 , and a “2-1” slit pattern  195   b - 1  in the first domain Da of the second pixel PX 2  may generate horizontal electric field components in a border area with the second domain Db of the first pixel PX 1 . Therefore, by using second slit patterns  195   b  disposed between a pair of adjacent pixels PX, liquid crystal molecules  302  disposed along the border between the pair of adjacent pixels PX may be adjusted to have an average azimuth angle  10 . 
     According to the illustrated exemplary embodiment, by arranging second silt patterns  195   b  in an alternate manner in each pair of adjacent pixels PX, the behavior of liquid crystal molecules  302  may be appropriately adjusted such that the liquid crystal molecules  302  are oriented to a direction of the average azimuth angle  310 . As a result, the visibility of an LCD  1  may be improved. 
     Referring to  FIG. 17 , second slit patterns  195   b  may be disposed in each of a plurality of pixels PX. The second slit patterns  195   b  may be disposed on one side of each of the plurality of pixels PX so as to adjust the azimuth angle of liquid crystal molecules  302  with the use of a fringe field between each pair of adjacent pixels PX. 
     More specifically, the second slit patterns  195   b  may be disposed on one side of each of the plurality of pixels PX. That is, the second slit patterns  195   b  may be disposed on the sides of first and fourth domains Da and Dd of each of the plurality of pixels PX so as to generate horizontal electric field components in the respective neighboring pixels PX and thus to move the liquid crystal molecules  302  to have an average azimuth angle  310 . That is, liquid crystal molecules  302  in a border area between the first domain Da of a second pixel PX 2  and the second domain Db of a first pixel PX 1  may be moved to a direction of the average azimuth angle  310 . Also, liquid crystal molecules  302  in a border area between the fourth domain Dd of the second pixel PX 2  and the third domain Dc of the first pixel PX 1  may be moved to the direction of the average azimuth angle  310 . In an alternative exemplary embodiment, the second slit patterns  195   b  may be provided on the sides of second domain Db and the third domain Dc of each of the plurality of pixels PX, thereby obtaining the same effect as that obtained by providing the second slit patterns  195   b  on the sides of the first and fourth domains Da and Dd of each of the plurality of pixels PX. 
     According to the exemplary embodiment, by arranging the second slit patterns  195   b  in an alternate manner between each pair of adjacent pixels PX, the behavior of liquid crystal molecules  302  may be appropriately adjusted such that the liquid crystal molecules  302  are oriented to the direction of the average azimuth angle  310 . As a result, the visibility of an LCD  1  may be improved. 
     Referring to  FIG. 18 , two second slit patterns  195   b  may be disposed on both sides of each of a plurality of pixels PX. More specifically, a second slit pattern  195   b  may be disposed at the lower bottom of a first pixel PX 1 , i.e., in a third domain Dc of the first pixel PX 1 , and another second silt pattern  195   b  may be disposed in a first domain Da of the first pixel PX 1 . 
     Accordingly, the third domain Dc of the first pixel PX 1  may be affected by a second slit pattern  195   b  in a first domain Da of a second pixel PX 2 , and as a result, the movement of liquid crystal molecules  302  in an edge area of the third domain Dc of the first pixel PX 1  may be facilitated. 
     The first domain Da of the second pixel PX 2  may also be affected by a second slit pattern  195   b  in the third domain Dc of the first pixel PX 1 , and as a result, the movement of liquid crystal molecules  302  in an edge area of the first domain Da of the second pixel PX 2  may be facilitated. 
     According to the illustrated exemplary embodiment, by arranging the second slit patterns  195   b  in an alternate manner in each pair of adjacent pixels PX, the behavior of liquid crystal molecules  302  may be appropriately adjusted such that the liquid crystal molecules  302  are oriented to a direction of an average azimuth angle  310 . As a result, the visibility of an LCD  1  may be improved. 
       FIG. 19  is an equivalent circuit diagram of a pixel of an LCD according to an exemplary embodiment of the invention,  FIG. 20  is a plan view of the pixel of the LCD of  FIG. 19 ,  FIG. 21  is a cross-sectional view taken along line of  FIG. 20 , and  FIG. 22  is a graph showing a gamma curve of the LCD of  FIG. 19 . In the description that follows,  FIGS. 1 to 5  will be referred to again for convenience. 
       FIG. 19  illustrates only one pixel PX, only one gate line GL, only one data line DL, and only one reference voltage line RL for convenience. However, in reality, a plurality of pixels may be arranged in a matrix of rows and columns, and may be respectively disposed near the intersections between a plurality of gate lines  121 , which extend in a row direction, and a plurality of data lines  171 , which extend in a column direction. 
     Referring to  FIGS. 19 and 20 , a pixel PX of an LCD  1  may include first, second and third switching devices QH, QL and Qc, which are implemented as TFTs, and first and second liquid crystal capacitors C 1  and C 2 , which include a dielectric body including a liquid crystal layer  300  (refer to  FIG. 2 ). 
     The sources (i.e., the input terminals) of the first and second switching devices QH and QL may be connected to the data line DL, the gates (i.e., the control terminals) of the first and second switching devices QH and QL may be connected to the gate line GL, and the gate (i.e., the control terminal) of the third switching device Qc may also be connected to the gate line GL. 
     A junction CP between the drain of the second switching device QL and the source of the third switching device Qc may be connected to a second sub-pixel electrode  191 L of the second liquid crystal capacitor C 2 , and the drain (i.e., the output terminal) of the first switching device QH may be connected to a first sub-pixel electrode  191 H of the first liquid crystal capacitor C 1 . Second ends of the first and second liquid crystal capacitors C 1  and C 2  may be connected to a common electrode. The drain (i.e., the output terminal) of the third switching device Qc may be connected to a sustain voltage line  131 . The second sub-pixel electrode  191   b  may be electrically connected to the partial pressure reference voltage line RL via the third switching device Qc. 
     In response to a gate-on signal Von being applied to the gate line GL, the first, second, and third switching devices QH, QL. and Qc, which are connected to the gate line GL, may be turned on. Accordingly, a data voltage applied to the data line DL may be applied to the first sub-pixel electrode  191 H via the first switching device QH that is turned on. The voltage applied to the second sub-pixel electrode  191 L may be divided by the third switching device Qc, which is connected in series to the second switching device QL. As a result, the voltage applied to the second sub-pixel electrode  191 L may become lower than the voltage applied to the first sub-pixel electrode  191 H. 
     Thus, the voltage that the first liquid crystal capacitor C 1  is charged with may differ from the voltage that the second liquid crystal capacitor C 2  is charged with. Since the voltage that the first liquid crystal capacitor C 1  is charged with may differ from the voltage that the second liquid crystal capacitor C 2  is charged with, the tilt angle of liquid crystal molecules may vary from a first sub-pixel PXH to a second sub-pixel PXL, and as a result, the luminance of the first sub-pixel PXH may differ from the luminance of the second sub-pixel PXL. 
     Therefore, by appropriately adjusting the voltage that the first liquid crystal capacitor C 1  is charged with and the voltage that the second liquid crystal capacitor C 2  is charged with, it is possible to make an image viewed from the sides of the LCD  1  become as similar as possible to an image viewed from the front of the LCD  1 . That is, the side visibility of the LCD  1  may be improved. 
     In the illustrated exemplary embodiment, the third switching device Qc, which is connected to the second liquid crystal capacitor C 2  and the partial pressure reference voltage line RL, may be provided to make the voltage that the first liquid crystal capacitor C 1  is charged with differ from the voltage that the second liquid crystal capacitor C 2  is charged with. In an alternative exemplary embodiment, the second liquid crystal capacitor C 2  may be connected to a step-down capacitor. 
     More specifically, in the alternative exemplary embodiment, a third switching device Qc having a first terminal connected to a step-down gate line, a second terminal connected to the second liquid crystal capacitor C 2 , and a third terminal connected to the step-down capacitor may be provided to allow the step-down capacitor to be charged with part of the electric potential that the second liquid crystal capacitor C 2  is charged with, and thus to set the voltage that the first liquid crystal capacitor C 1  is charged with and the voltage that the second liquid crystal capacitor C 2  is charged with to differ from each other. In another alternative exemplary embodiment, the first and second liquid crystal capacitors C 1  and C 2  may be connected to different data lines so as to receive different data voltages and thus to set the voltage that the first liquid crystal capacitor C 1  is charged with and the voltage that the second liquid crystal capacitor C 2  is charged with to differ from each other. Various other methods than those set forth herein may be used to set the voltage that the first liquid crystal capacitor C 1  is charged with and the voltage that the second liquid crystal capacitor C 2  is charged with to differ from each other. 
     Referring to  FIGS. 20 to 22 , an LCD  1  may include first and second panels  100  and  200 , which face each other, and the liquid crystal layer  300 , which is disposed between the first and second panels  100  and  200 . 
     The first panel  100  includes a first substrate  100 , the first, second, and third switching devices QH, QL, and Qc (refer to  FIG. 19 ), a gate line  121 , to which the first, second, and third switching devices QH, QL, and Qc are connected, a partial pressure reference voltage line  131 , a data line  171 , and a pixel electrode  191 . The pixel electrode  191  may include the first and second sub-pixel electrodes  191 H and  191 L. 
     The partial pressure reference voltage line  131  may include first sustain electrodes  135  and  136  and a reference voltage  137 . The partial pressure reference voltage line  131  may also include second sustain electrodes  138  and  139 , which are not connected to the partial pressure reference voltage line  131 , but overlap the second sub-pixel electrode  191 L. 
     In the first panel  100 , a gate conductor including the gate line  121 , the partial pressure reference voltage line  131 , and the sustain electrode line  135 ,  136 ,  138  and  139  may be disposed on the first substrate  110 . In an exemplary embodiment, the first substrate  110  may include a plastic material or glass such as, for example, soda lime glass or borosilicate glass. 
     The gate line  121  and the partial pressure reference voltage line  131  may extend in one direction, for example, a horizontal direction, and may transmit a gate signal. The gate line  121  may include first and second gate electrodes  124 H and  124 L, which partially protrude from the gate line  121  between the first and second sub-pixel electrodes  191 H and  191 L, and a third gate electrode  124   c , which protrude upward. The first and second gate electrodes  124 H and  124 L may be unitary to provide a single protrusion. 
     In the exemplary embodiment, a step-down gate line, which is different from the gate line  121 , may also be provided. 
     The partial pressure reference voltage line  131  may extend in the horizontal direction and may transmit a predefined voltage such as a common voltage. The partial pressure reference voltage line  131  may include the first sustain electrodes  135  and  136  and the second sustain electrodes  138  and  139 , which extend downward. 
     A first vertical sustain electrode  135 , which is one of the first sustain electrodes  135  and  136 , may be provided along a vertical edge of the first sub-pixel electrode  191 H, and a second vertical sustain electrode  138 , which is one of the second sustain electrodes  138  and  139 , may be provided along a vertical edge of the second sub-pixel electrode  191 L. A second horizontal sustain electrode  139  may be disposed between a horizontal edge of the second sub-pixel electrode  191 L and a horizontal edge of the first sub-pixel electrode  191 H, and a first horizontal sustain electrode  136  and the second horizontal sustain electrode  139  may be respectively provided along the horizontal edge of the second sub-pixel electrode  191 L and the horizontal edge of the first sub-pixel electrode  191 H. 
     The first vertical sustain electrode  135  and the first horizontal sustain electrode  136  may be provided along the edges of the first sub-pixel electrode  191 H and may partially overlap the first sub-pixel electrode  191 H, and the second vertical sustain electrode  138  and the second horizontal sustain electrode  139  may be provided along the edges of the second sub-pixel electrode  191 L and may partially overlap the second sub-pixel electrode  191 L. 
     The first and second horizontal sustain electrodes  136  and  139  are illustrated in  FIG. 20  as being separate from each other. However, the first and second horizontal sustain electrodes  136  and  139  may be electrically connected to the respective horizontal sustain electrodes in the respective vertically neighboring pixels PX to have a shape of a ring and to surround the first and second sub-pixel electrodes  191 H and  191 L. 
     The gate line  121 , the partial pressure reference voltage line  131 , and the sustain electrode line  135 ,  136 ,  138 , and  139  may include the same material(s) and may be disposed on the same layer. In an exemplary embodiment, the gate line  121 , the partial pressure reference voltage line  131 , and the sustain electrode line  135 ,  136 ,  138 , and  139  may include an aluminum (Al)-based metal such as Al or an Al alloy, a silver (Ag)-based metal such as Ag or an Ag alloy, a copper (Cu)-based metal such as Cu or a Cu alloy, a molybdenum (Mo)-based metal such as Mo or a Mo alloy, chromium (Cr), titanium (Ti) or tantalum (Ta). 
     In an exemplary embodiment, the gate line  121 , the partial pressure reference voltage line  131 , and the sustain electrode line  135 ,  136 ,  138 , and  139  may have a multilayer structure including two conductive films having different physical properties, wherein one of the two conductive films may include a low-resistance metal, for example, an Al-based metal, an Ag-based metal, or a Cu-based metal, so as to reduce signal delays or voltage drops in the gate line  121 . 
     A gate insulating layer  115  may be disposed on an entire surface of the first substrate  110  where the gate line  121 , the partial pressure reference voltage line  131 , and the sustain electrode line  135 ,  136 ,  138 , and  139  are provided. In an exemplary embodiment, the gate insulating layer  115  may include silicon oxide (SiOx) or a silicon nitride (SiNx), for example. 
     Semiconductor layers  154 H,  154 L, and  154 C may be disposed on the gate insulating layer  115 , and may at least partially overlap gate electrodes  124 H,  124 L, and  124 C. In an exemplary embodiment, the semiconductor layers  154 H,  154 L, and  154   c  may include amorphous silicon (a-Si), polycrystalline silicon (poly-Si), or an oxide semiconductor including zinc oxide (ZnO), for example. 
     A plurality of ohmic contacts (not illustrated) may be disposed on the semiconductor layers  154 H,  154 L, and  154 C. A first ohmic contact (not illustrated) may be disposed on the first semiconductor layer  154 H. 
     A data conductive line may be disposed on the semiconductor layers  154 H,  154 L, and  154 C. The data conductive line may include the data line  171 , which extends in a vertical direction to intersect the gate line  121 . 
     The data line  171  may transmit a data signal and may extend mostly in the vertical direction to intersect the gate line  121  and the partial pressure reference voltage line  131 . The data line  171  may extend toward the first and second gate electrodes  124 H and  124 L, and may include first and second source electrodes  173 H and  173 L, which are connected to each other. 
     In addition to the first and second source electrodes  173 H and  173 L, which are connected to the data line  171 , the data line  171  may also include a first drain electrode  175 H, which faces, and is isolated from, the first source electrode  173 H, a second drain electrode  175 L, which faces, and is isolated from, the second source electrode  173 L, a third source electrode  173 C, which is electrically connected to the second drain electrode  175 L, and a third drain electrode  175 C, which faces, and is isolated from, the third source electrode  173 C. 
     The ends of the first and second drain electrodes  175 H and  175 L may be partially surrounded by the first and second source electrodes  173 H and  173 L. One wide end portion of the second drain electrode  175 L may extend to provide the third source electrode  173 C. A wide end portion of the third drain electrode  175 C may overlap a reference electrode  137  and may be connected to a third contact hole  185 C by a connection electrode  95 . The end of the third source electrode  173 C may be partially surrounded by the third drain electrode  175 C having a U-shape. 
     The semiconductor layers  154 H,  154 L, and  154 C may have substantially the same shape in a plan view as data conductors  171 ,  175 H,  175 L, and  175 C and resistive contact members  165 H,  165 L, and  165 C, which are disposed below the data conductors  171 ,  175 H,  175 L, and  175 C, except for in channel areas between the source electrodes  173 H,  173 L, and  173 C and the drain electrodes  175 H,  175 L, and  175 C. That is, the semiconductor layers  154 H,  154 L, and  154 C may be exposed in some areas, for example, between the source electrodes  173 H,  173 L, and  173 C and the drain electrodes  175 H,  175 L, and  175 C, instead of being blocked by the data conductors  171 ,  175 H,  175 L, and  175 C. 
     The data line  171  may directly contact the semiconductor layers  154 H,  154 L, and  154 C and may thus provide an ohmic contact. The data line  171  may be a single layer including a low-resistance material so as for the data line  171  to perform the functions of an ohmic contact. In an exemplary embodiment, the data line  171  may include Cu, Al or Ag. 
     In an exemplary embodiment, to improve the ohmic contact properties of the data line  171  relative to the semiconductor layers  154 H,  154 L, and  154 C, the data line  171  may have a single- or multilayer structure including Ni, Co, Ti, Ag, Cu, Mo, Al, beryllium (Be), niobium (Nb), gold (Au), iron (Fe), selenium (Se), or Ta, for example. As examples of the multilayer structure, a double layer structure may include Ta/Al, Ta/Al, Ni/Al, Co/Al, Mo (or Mo alloy)/Cu, Mo (or Mo alloy)/Cu, Ti (or Ti alloy)/Cu, TiN (or TiN alloy)/Cu, Ta (or Ta alloy)/Cu, or TiOx/Cu, and a triple layer structure may include Ti/Al/Ti, Ta/Al/Ta, Ti/Al/TiN, Ta/Al/TaN, Ni/Al/Ni, or Co/Al/Co, for example. 
     In an exemplary embodiment, to increase the aperture ratio of a lower substrate where TFTs are provided, the gate line  121  and the data line  171  may both include a transparent conductive material such as indium tin oxide (“ITO”), indium zinc oxide (“IZO”), or Al-doped zinc oxide (“AZO”). 
     The first, second, and third gate electrodes  124 H,  124 L, and  124 C, the first, second, and third source electrodes  173 H,  173 L, and  173 C, and the first, second, and third drain electrodes  175 H,  175 L, and  175 C may provide first, second, and third TFTs QH, QL, and Qc, respectively, together with the first, second and third semiconductor layers  154 H,  154 L, and  154 C, respectively, and the channels of the first, second, and third TFTs QH, QL, and Qc may be provided in the first, second and third semiconductor layers  154 H,  154 L, and  154 C, respectively, between the first, second, and third source electrodes  173 H,  173 L, and  173 C, respectively, and the first, second, and third drain electrodes  175 H,  175 L, and  175 C, respectively. 
     A protective layer  180  may be disposed on the data conductors  171 ,  175 H,  175 L, and  175 C and on exposed parts of the semiconductor layers  154 H,  154 L, and  154 C. In an exemplary embodiment, the protective layer  180  may be provided as an inorganic layer or an organic layer. To protect the semiconductor layers  154 H,  154 L, and  154 C, the protective layer  180  may have a double-layer structure including a lower inorganic layer and an upper organic layer or a triple-layer structure including a lower inorganic layer, an organic layer on the lower inorganic layer, and another inorganic layer on the organic layer. A color filter may be used as an organic layer of the protective layer  180 . 
     In an exemplary embodiment, a lower protective layer  180   p  may be disposed on the data conductors  171 ,  175 H,  175 L, and  175 C and the exposed parts of the semiconductor layers  154 H,  154 L, and  154 C, and may include an inorganic insulating material such as SiNx or SiOx. 
     An organic layer may be disposed on the lower protective layer  180   p  as part of the protective layer  180 . A color filter  1800  may be used as the organic layer. The color filter  1800  may extend in the vertical direction along the data line  171 , and may display one of the three primary colors (i.e., red, green and blue). The color filter  1800  may overlap the data line  171  from above the data line  171 . 
     An upper protective layer  180   q  may be disposed on the lower protective layer  180   p , which is exposed by the color filter  1800  and one or more openings. The upper protective layer  180   q  may prevent the color filter  1800  from being detached, and may suppress the contamination of the liquid crystal layer  300  with an organic material such as a solvent that may be introduced from the color filter  1800  so as to prevent defects such as afterimages that may occur during the driving of the LCD  1 . In an exemplary embodiment, the upper protective layer  180   q  may include an inorganic insulating material such as SiNx or SiOx or an organic material. 
     First and second contact holes  185 H and  185 L, which expose the ends of the first and second drain electrodes  175 H and  175 L, respectively, may be provided in the lower protective layer  180   p , the color filter  1800 , and the upper protective layer  180   q.    
     The pixel electrode  191  is disposed on the upper protective layer  180   q . The pixel electrode  191  may be connected to the first and second drain electrodes  175 H and  175 L via the first and second contact holes  185 H and  185 L, respectively. In an exemplary embodiment, the pixel electrode  191  may include a transparent conductive material such as ITO or IZO. In response to a voltage being received via the first and second drain electrodes  175 H and  175 L, the pixel electrode  191  may generate an electric field with a common electrode  270 , which is disposed between the first and second panels  100  and  200 , and may thus rotate liquid crystal molecules  302  in the liquid crystal layer  300 , which is disposed between the first and second panels  100  and  200 . 
     The pixel electrode  191  may receive a data voltage via the TFTs QH, QL, and Qc, which are controlled by a gate signal. 
     The pixel electrode  191  may be disposed in the pixel PX, which is defined by the gate line  121  and the data line  171 . 
     The pixel electrode  191  may include the first and second sub-pixel electrodes  191 H and  191 L, which are separated from each other by the gate line  121 , are disposed in upper and lower parts, respectively, of a pixel region, and are adjacent to each other in the column direction. 
     The first sub-pixel electrode  191 H may include a central electrode  192 H, which is disposed in a central part of the first sub-pixel electrode  191 H, and a plurality of fine branches  194 H, which diagonally extend from the central electrode  192 H, and the second sub-pixel electrode  191 L may include a central electrode  192 L, which is disposed in a central part of the second sub-pixel electrode  191 L, and a plurality of fine branches  194 L, which diagonally extend from the central electrode  192 L. The fine branches  194 H and the fine branches  194 L may both include first branch electrodes  194   a , second branch electrodes  194   b , third branch electrodes  194   c , and fourth branch electrodes  194   d  (refer to  FIG. 1 ). 
     In addition to the central electrodes  192 H and  192 L, the fine branches  194 H, and the fine branches  194 L, the pixel electrode  191  may also include side electrodes  193 H and side electrodes  193 L, which are disposed along the edges of the pixel PX 
     In the pixel PX, the central electrode  192 H, the fine branches  194 H, and the side electrodes  193 H of the first sub-pixel electrode  191 H may be unitary to receive the same voltage, and the central electrode  192 L, the fine branches  194 L, and the side electrodes  193 L of the second sub-pixel electrode  191 L may be unitary to receive the same voltage. A plurality of domains may be provided in the pixel PX by horizontal and vertical cutout portions  283  and  286 . 
     The pixel electrode  191 , which includes the first and second sub-pixel electrodes  191 H and  191 L, may include the side electrodes  193 H, the side electrodes  193 L, first slit patterns  195   a H, first slit patterns  195   a L, second slit patterns  195   b H, and second slit patterns  195   b L. 
     The second panel  200  includes a second substrate  210 , which faces the first substrate  110 , and the common electrode  270 . The common electrode  270  may be disposed on the second substrate  210 , which includes a transparent glass or plastic material. 
     A light-blocking member  330  and the color filter  1800  may be disposed on the first panel  100  or may be selectively disposed on the second panel  200 . More specifically, the light-blocking member  330 , the color filter  1800 , an overcoat layer, and a second alignment layer may be provided on the second substrate  210 . In the illustrated exemplary embodiment, the color filter  1800  and the light-blocking member  300  are disposed on the first panel  100 . 
     By arranging the color filter  1800  and the light-blocking member  330  on the first substrate  110 , a misalignment between wires that may occur in a curved display device may be prevented. Also, in a case when the alignment direction of the liquid crystal molecules  320  is determined using the second alignment layer, disclination lines that may be generated due to misaligned liquid crystal molecules may be prevented. 
     The arrangement of the light-blocking member  330 , the color filter  1800 , the overcoat layer, and the second alignment layer on the second substrate  210  will hereinafter be described. The color filter  1800 , which is of one of a plurality of colors, may be disposed on the second substrate  210 , and the light-blocking member  330  may be disposed along the edges of the color filter  1800 . The color filter  1800  may serve as a filter for transmitting light of a predetermined wavelength therethrough, and the light-blocking member  330 , which may also be also referred to as a black matrix, may prevent light leakage and the mixing of the color of the color filter  1800  with the colors of other color filters  1800 . 
     The overcoat layer and the second alignment layer may be selectively disposed in the second panel  200 . The overcoat layer may be disposed on the entire surface of the second substrate  210  where the color filter  1800  and the light-blocking member  330  are provided. The overcoat layer may include an insulating material and may provide a flat surface. The overcoat layer may be optional. 
     The common electrode  270  may be disposed on the overcoat layer. The second alignment layer may be disposed on the common electrode  270 . The second alignment layer may be a vertical alignment layer. The second alignment layer may be optional. 
     A cutout  280  including a first cutout portion  283 , which is provided by partially cutting out the common electrode  270  in the horizontal direction, and a second cutout portion  286 , which is provided by partially cutting out the common electrode in the vertical direction, may be provided in the common electrode  270 . The first and second cutout portions  283  and  286  may have the shape of a cross in a plan view, and may extend beyond the edges of the first and second sub-pixel electrodes  191 H and  191 L. Since the cutout  280  of the common electrode  270  may extend beyond the edges of the pixel electrode  191 , a horizontal electric field may stably reach the sides of the pixel PX, and accordingly, the alignment of the liquid crystal molecules  302  may be also properly adjusted in areas along the sides of the pixel PX. 
     In an exemplary embodiment, the width of the first and second cutout portions  283  and  286  may be about three times or less the thickness of the liquid crystal layer  300 , i.e., the cell gap of the LCD  1 . In an exemplary embodiment, the width of the first and second cutout portions  283  and  286  may be in the range of about 2 μm to about 5 μm, for example. 
     The first and second sub-pixel electrodes  191 H and  191 L may be connected to the first and second drain electrodes  175 H and  175 L, respectively, via the first and second contact holes  185 H and  185 L, respectively, and may thus receive a data voltage from the first and second drain electrodes  175 H and  175 L, respectively. 
     The sides of each of the fine branches  194  may distort an electric field and may thus generate horizontal electric field components that determine the alignment direction of the liquid crystal molecules  302 . The horizontal electric field components may move the liquid crystal molecules  302  and may thus align the liquid crystal molecules  302  in directions parallel to the longitudinal directions of the first branch electrodes  194   a , the second branch electrodes  194   b , the third branch electrodes  194   c , and the fourth branch electrodes  194   d . Accordingly, as discussed above with reference to  FIGS. 1 to 5 , the liquid crystal molecules  302  may be tilted in the directions parallel to the longitudinal directions of the first branch electrodes  194   a , the second branch electrodes  194   b , the third branch electrodes  194   c , and the fourth branch electrodes  194   d . Since the pixel electrode  191  may include four different domains, i.e., first to fourth domains Da to Dd that differ from one another in terms of the longitudinal direction of the fine branches  194 , the liquid crystal molecules  302  may be tilted in about four directions, and four domains that differ from one another in terms of the alignment direction of the liquid crystal molecules  302  may be provided in each sub-pixel. 
     Liquid crystal molecules  302  unevenly aligned along the edges of each domain may also be realigned in a direction similar to a direction of an average azimuth angle  310  with the use of the second slit patterns  195   b L and the second slit patterns  195   b H. 
     The direction in which the liquid crystal molecules  302  are tilted may be diversified from one domain to another domain, and in each domain, the liquid crystal molecules  302  may be aligned to have the average azimuth angle  310 . Accordingly, the viewing angle of the LCD  1  may be improved. 
     Referring to  FIG. 22 , the LCD  1  may reduce grayscale inversion not only through the distortion of an electric field, but also through the alignment of the liquid crystal molecules and the modulation of voltages with the geometric surface structure thereof. Grayscale inversion may be indicated by a gamma curve. 
     The gamma curve may be defined by the following equation: 
     
       
         
           
             
               
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     The gamma curve may show the variation of luminance, at the front of the LCD  1 , with grayscale. 
     Accordingly, the variation of luminance, at sides of the LCD  1 , with grayscale may be determined. 
     As illustrated in  FIG. 22 , the difference in luminance between the sides and the front of the LCD  1  may be reduced, and as a result, the distortion of the gamma curve (a difference between the side visibility and the front visibility of the LCD  1 ) may be reduced. That is, the transmittance and the visibility of the LCD  1  may be improved, and as a result, the distortion of the gamma curve may be reduced. 
     While the invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes may be made therein without departing from the spirit and scope of the invention as defined by the following claims. The exemplary embodiments should be considered in a descriptive sense only and not for purposes of limitation. 
     Although certain exemplary embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the invention is not limited to such exemplary embodiments, but rather to the broader scope of the presented claims and various obvious modifications and equivalent arrangements.