Liquid crystal display

A liquid crystal display includes a first panel including a first substrate, a first electrode which is disposed on the first substrate and which includes a stem unit including a horizontal stem and a vertical stem dividing a pixel into domains, a branch unit including branch electrodes and extending from at least one stem of the stem unit in one direction, and an external bundling electrode unit connected to an end of at least one of the branch electrodes and disposed along an edge of the pixel, a first slit pattern which is defined in the branch unit, a second slit pattern which contacts the vertical stem and is disposed parallel to the horizontal stem, a third slit pattern which contacts the horizontal stem and is disposed parallel to the vertical stem, and a protrusion unit which is disposed on an outer circumference of the external bundling electrode unit.

This application claims priority to Korean Patent Application No. 10-2015-0089968 filed on Jun. 24, 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

The exemplary embodiments relate to a liquid crystal display (“LCD”).

2. Description of the Related Art

A liquid crystal display (“LCD”), which is one of the most widely used flat panel displays, generally includes two display panels, which is provided with field generating electrodes such as pixel electrode and common electrode, and a liquid crystal layer disposed therebetween. The LCD is configured such that a voltage is applied to the field generating electrodes to generate an electric field in the liquid crystal layer, and, through the electrical field, the orientation of liquid crystal molecules is determined and the polarization of incident light is controlled, thereby displaying an image.

Among LCDs, a vertically-aligned mode LCD can form a plurality of domains, in which orientation directions are different, in one pixel in order to realize a wide viewing angle.

As an example of means for forming a plurality of domains, there is a method of forming incisions such as slits in each of the field generating electrodes. In this method, liquid crystals are rearranged by the fringe field generated between the edge of the incision and the field generating electrode facing this edge, thereby forming a plurality of domains.

In the vertically-aligned mode LCD, it is important to secure a wide viewing angle. For this purpose, a method of forming incisions, such as fine slits, in the field generating electrode or a method of forming protrusions on the field generating electrode is used. Since incisions or protrusions determine the tilt direction of liquid crystal molecules, the incisions or protrusions determine are appropriately disposed to disperse the tilt direction of liquid crystal molecules in various directions, thereby widening a viewing angle.

SUMMARY

In the vertically-aligned mode liquid crystal display (“LCD”), lateral visibility may deteriorate compared to front visibility.

Exemplary embodiments of the invention provide an LCD with improved response speed 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 set forth below.

According to an exemplary embodiment of the invention, an LCD includes a first panel including a first substrate, a first electrode which is disposed on the first substrate and which includes a stem unit including a horizontal stem and a vertical stem dividing a pixel into a plurality of domains, a branch unit including a plurality of branch electrodes and extending from at least one stem of the stem unit in one direction, and an external bundling electrode unit connected to an end of at least one of the branch electrodes and disposed along an edge of the pixel, a first slit pattern which is disposed on the branch unit to allow the branch electrodes to be spaced apart from each other, a second slit pattern which contacts the vertical stem and is disposed in a direction parallel to the horizontal stem, a third slit pattern which contacts the horizontal stem and is disposed in a direction parallel to the vertical stem, and a protrusion unit which is disposed on an outer circumference of the external bundling electrode unit and protrudes in a direction perpendicular to the first substrate, a second panel including a second substrate, and a second electrode disposed on the second substrate and facing the first electrode, and a liquid crystal layer disposed between the first panel and the second panel.

In an exemplary embodiment, the second slit pattern may be connected to an end of a lateral side of the first slit pattern, and the third slit pattern may be connected to ends of upper and lower sides of the first slit pattern.

In an exemplary embodiment, the second and third slit patterns may be disposed to allow the external bundling electrode unit to be spaced apart from the ends of the branch electrodes.

In an exemplary embodiment, the branch electrodes and slit patterns, which may be disposed in a domain and another domain adjacent to the domain, are alternately arranged.

In an exemplary embodiment, the pitches of the branch electrodes and the first slit pattern may be in a range of about 4 micrometers (μm) to about 8 μm, for example.

In an exemplary embodiment, the LCD may further include a first polarizing plate having a polarization axis aligned on the first panel in one direction, and a second polarizing plate having a polarization axis aligned on the second panel in a direction perpendicular to the one direction, wherein the extending direction of the branch unit is in a range of about 30 degrees (°) to about 60° with respect to the polarization axis of each of the first and second polarizing plates.

In an exemplary embodiment, the first electrode may be configured such that the external bundling electrode unit which contacts the protrusion unit and may be disposed in a direction parallel to the protrusion unit, the stem unit which is connected to the external bundling electrode unit and includes the horizontal and vertical stems dividing the pixel into the plurality of domains, and the branch unit which extends to the horizontal and vertical stems to be connected to the external bundling electrode unit are integrally provided.

In an exemplary embodiment, the widths of the horizontal and vertical stems may be in a range of about 2 μm to about 5 μm.

In an exemplary embodiment, the height of the protrusion unit may be in a range of about 0.5 μm to about 2 μm.

In an exemplary embodiment, the width of the external bundling electrode unit may be in a range of about 2 μm to about 4 μm.

In an exemplary embodiment, the widths of the second and third slit patterns and the external bundling electrode unit are may be a range of about 4 μm to about 8 μm.

In an exemplary embodiment, the widths of the protrusion unit and the external bundling electrode unit may be in a range of about 7 μm to about 9 μm.

In an exemplary embodiment, the width of the protrusion unit may be in a range of about 3 μm to about 5 μm.

In an exemplary embodiment, the first electrode disposed in the pixel may include a first region in which the branch unit is disposed adjacent to the stem unit, and a second region in which one or more of the external bundling electrodes and the protrusions, which are connected to the end of any one of the branch electrodes, are spaced apart from the stem unit, wherein the external bundling electrode unit and the protrusion unit disposed in the second region provide a vector for rotating the liquid crystal molecules in the second region in a direction similar to the average liquid crystal azimuth of the liquid crystal molecules in the first region.

In an exemplary embodiment, the extending direction of the branch electrodes may be identical with the average liquid crystal azimuth of the liquid crystal molecules.

In an exemplary embodiment, the first electrode may further include a plurality of sub-electrodes disposed in one pixel, and a connection electrode connecting the sub-electrodes adjacent to each other.

In an exemplary embodiment, the connection electrodes may be disposed in an intermediate unit spacing the adjacent sub-electrodes apart from each other.

In an exemplary embodiment, the protrusion unit may be disposed in the intermediate unit.

In an exemplary embodiment, the protrusions may be disposed at the ends of the horizontal and vertical stems and the corners of the pixel.

In an exemplary embodiment, the protrusion unit may be disposed at the edge of the pixel excluding the corner of the pixel.

Other features and exemplary embodiments will be apparent from the following detailed description, the drawings, and the claims.

DETAILED DESCRIPTION

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.

Exemplary embodiments of the invention will now be explained with reference to the drawings.

FIG. 1is a plan view of an LCD according to an exemplary embodiment of the invention, andFIG. 2is a cross-sectional view taken along line I-I′ of the LCDFIG. 1.FIG. 3is an equivalent circuit diagram for one pixel of the LCD according to an exemplary embodiment of the invention, andFIG. 4is an enlarged plan view of one pixel according to an exemplary embodiment of the invention.

InFIGS. 1 and 3, for the convenience of explanation, one pixel PX, and a gate line GL, a data line DL, and a partial reference voltage line RL related therewith are shown. However, a plurality of pixels may be arranged in a matrix of rows and columns, and may also be arranged around the intersections of a plurality of gate lines121extending in the row direction and a plurality of data lines171extending in the column direction.

Referring toFIGS. 1 and 2, an LCD includes a first panel100and a second panel200, which face each other, and a liquid crystal layer300disposed between the first panel100and the second panel200.

The first panel100may include a first substrate110, a first electrode191and a first alignment film (not shown), which are sequentially disposed on one side of the first substrate110, and a first polarizing plate140which is disposed on the other side of the first substrate110. Here, the first electrode191provided in the first panel100, for example, may be a pixel electrode.

The second panel200may include a second substrate210, a second electrode270and a second alignment film, which are sequentially disposed on one side of the second substrate210, and a second polarizing plate240which is disposed on the other side of the second substrate210. Here, the second electrode270provided in the second panel200, for example, may be a common electrode.

The first panel100or the second panel200may further include switching elements QH, QL, and Qc (refer toFIG. 3), a color filter1800, and a light blocking member330. In another exemplary embodiment, one of the first polarizing plate140and second polarizing plate240may be omitted. In other exemplary embodiment, any one or both of the first alignment film and the second alignment film may be omitted.

The liquid crystal layer300may include a liquid crystal having a negative dielectric anisotropy or a liquid crystal having a positive dielectric anisotropy. In the following embodiments, there is exemplified a case that the liquid crystal layer300includes a liquid crystal having a negative dielectric anisotropy, for example. When an electric field does not exist between the first and second electrodes191and270, the liquid crystal molecules302in the liquid crystal layer300may be arranged such that the major axis thereof is disposed in a direction perpendicular to the surface of the first and second alignment films. Further, the liquid crystal molecules302may be arranged such that the major axis thereof has a pretilt angle to the thickness direction of the liquid crystal layer300.

Hereinafter, the first panel100and the second panel200will be described in detail, respectively.

First, the first panel100may include a first substrate110, a first switching element QH, a second switching element QL, and a third switching element Qc, and a gate line121, a partial reference line131, a data line, and a pixel electrode191, which are electrically connected with these switching elements QH, QL, and Qc. The pixel electrode191includes a first sub-pixel electrode191H and a second sub-pixel electrode191L. The first subpixel electrode191H may include a horizontal stem192aH, a vertical stem192bH, an external bundling electrode unit193H and a branch electrode194H, and the second subpixel electrode191L may include a horizontal stem192aL, a vertical stem192bL, an external bundling electrode unit193L and a branch electrode194L. A slit pattern195H may include slit patterns195aH195bH and195cH, and slit pattern195L may include slit patterns195aL,195bL and195cL.

The partial reference line131may include first sustain electrode lines135and136and a reference electrode137. Each of the first sustain electrode lines135and136is not connected to the partial reference line131in the drawings, but is provided with second sustain electrodes138and139overlapping the second sub-pixel electrode191L.

The first panel100is provided with a plurality of gate conductors including a plurality of gate lines121, a partial reference line131, and a plurality of sustain electrode lines, on the first substrate110. In an exemplary embodiment, the first substrate110may include glass or plastic such as soda-lime glass or borosilicate glass.

The gate lines121and the partial reference line131may be arranged in one direction, for example, length direction (e.g., horizontal direction in a plan view), and may transmit gate signals. The gate line121located between the first sub-pixel electrode191H and the second sub-pixel electrode191L may include a first gate electrode124H and a second gate electrode124L which partially protrude from this gate line121, and a third gate electrode124cwhich protrudes upwards. Here, the first gate electrode124H and the second gate electrode124L may be connected with each other to provide one protrusion.

The gate line121and other step-down gate lines may be respectively arranged.

The partial reference line131extends in the horizontal direction, and may transmit a determined voltage such as a common voltage. The partial reference line131may include first sustain electrodes135and136, and may further include second sustain electrodes138and139which extend downwards.

Specifically, in the first sustain electrodes135and136, the first vertical sustain electrode135is provided along the vertical edge of the first pixel electrode191H. Further, in the second sustain electrodes138and139, the second vertical sustain electrode138is provided along the longitudinal edge of the second pixel electrode191L. In the second sustain electrodes138and139, the second horizontal sustain electrode139is located between the horizontal edge of the second pixel electrode191L and the horizontal edge of the first pixel electrode191H, and the first and second horizontal sustain electrodes136and139may be provided along the two horizontal edges.

Consequently, the first vertical sustain electrode135and the first horizontal sustain electrode136are along the edge of the first pixel electrode191H to at least partially overlap with the first pixel electrode191H, and the second vertical sustain electrode138and the second horizontal sustain electrode139are along the edge of the second pixel electrode191L to at least partially overlap with the second pixel electrode191L.

Although it is shown inFIG. 1that the first horizontal sustain electrode136located at the upper portion ofFIG. 1and the second horizontal sustain electrode139located at the lower portion ofFIG. 1are likely to be separated from each other, the above two horizontal sustain electrodes136and139, which are disposed in the adjacent upper and lower pixels PX, are electrically connected with each other to surround the sub-pixel electrodes191H and191L belonging to one pixel in a ring shape, respectively.

Each of the gate line121, partial reference line131, and sustain electrode lines135,136,138, and139may include the same material, and may be disposed on the same layer. In an exemplary embodiment, each of the gate line121, partial reference line131, and sustain electrode lines135,136,138, and139may include aluminum-based metals such as aluminum (Al) and aluminum alloys, silver-based metals such as silver (Ag) and silver alloys, copper-based metals such as copper (Cu) and copper alloys, molybdenum-based metals such as molybdenum (Mo) and molybdenum alloys, chromium (Cr), titanium (Ti), or tantalum (Ta).

Further, each of the gate line121, partial reference line131, and sustain electrode lines135,136,138, and139may have a multi-layer structure including two conductive films (not shown) whose physical properties are different from each other. In an exemplary embodiment, in the two conductive films, one conductive film may include a metal having low resistivity, such as an aluminum (Al)-based metal, a silver (Ag)-based metal, or a copper (Cu)-based metal, in order to reduce signal delay or voltage drop.

A gate insulating film115may be disposed on the entire surface of the first substrate110provided with the gate line121, partial reference line131, and sustain electrode lines135,136,138, and139. In an exemplary embodiment, the gate insulating film may include silicon oxide (SiOx) or silicon nitride (SiNx), for example.

Semiconductor layers154H,154L, and154cmay be disposed on the gate insulating film115. The semiconductor layers154H,154L, and154cmay be disposed such that they at least partially overlap with gate electrodes124H,124L, and124c. In an exemplary embodiment, each of the semiconductor layers154H,154L, and154cmay include oxide semiconductor including amorphous silicon, polycrystalline silicon, or zinc oxide (ZnO), for example.

A plurality of resistive (ohmic) contact members163H,165H,163L,165L,163c, and165cmay be disposed on the semiconductor layers154H,154L, and154c. Like the first resistive contact member disposed on the first semiconductor layer154H, these resistive contact members163H,165H,163L,165L,163c, and165cmay be disposed on their respective regions.

A plurality of data lines171including a first source electrode173H and a second source electrode173L, and a plurality of data conductors including a first drain electrode175H, a second drain electrode175L, a third source electrode173cand a third drain electrode175care disposed on the resistive contact members163H,165H,163L,165L,163c, and165cand the gate insulating film115. The data conductors and the semiconductors and resistive contact members located thereunder may be simultaneously provided using one mask. Further, each of the data lines171includes a wide end portion (not shown) for connection with another layer or an external driving circuit.

A data conductive layer is disposed on the semiconductor layers154H,154L, and154c. The data conductive layer may include the data lines171extending in the vertical direction so as to cross the gate line121.

The data lines171transmit data signals, and extend in the vertical direction to intersect with the gate lines121and the partial reference line131. Each of the data lines171extends toward the first gate electrode124H and the second gate electrode124L, and may include the first source electrode173H and the second source electrode173L, which are connected with each other.

The data conductive layer may include the first source electrode173H and the second source electrode173L, which are connected to the data line171, the first drain electrode175H, which is spaced apart from the first source electrode173H and faces the source electrode173H, the second drain electrode175L, which is spaced apart from the second source electrode173L and faces the second source electrode173L, the third source electrode173c, which is electrically connected with the second source electrode173L, and the third drain electrode175c, which is spaced apart from the third source electrode173cand faces the third source electrode173c.

The end portions of the first drain electrode175H and the second drain electrode175L are partially surrounded by the first source electrode173H and the second source electrode173L. One wide end portion of the second drain electrode175L extends again to provide a third source electrode173c. One wide end portion of the third drain electrode175coverlaps with the reference electrode137to be connected to a third contact hole185c, and the other end portion thereof having a U-shape partially surround the third source electrode173c.

In an exemplary embodiment, the semiconductor layers154H,154L, and154cmay have a substantially same plane shape with the data conductors171,175H,175L, and175cand the resistive contact members164H,164L, and164clocated thereunder, except for the channel regions between the source electrodes173H,173L, and173cand the drain electrodes175H,175L, and175c. That is, the semiconductor layers154H,154L, and154care provided with portions including the channel regions exposed by, i.e., not covered by, the data conductors171,175H,175L, and175cbetween the source electrodes173H,173L, and173cand the drain electrodes175H,175L, and175c.

The data lines171directly contact the semiconductor layers154H,154L, and154cto provide ohmic contact. Each of the data lines171may be a single layer including a low-resistance material in order to perform an ohmic contact role together with the semiconductor layers154H,154L, and154c. In an exemplary embodiment, each of the data lines171may include Cu, Al, or Ag, for example.

As such, the first, second and third gate electrodes124H/124L/124c, the first, second and third source electrodes173H/173L/173c, and the first, second and third drain electrodes175H/175L/175crespectively define first, second and third thin film transistors (“TFTs”) QH/QL/Qc together with the first, second and third semiconductor layers154H/154L/154c, respectively. In this case, the channels of the TFTs may be provided in the semiconductor layers154H/154L/154cbetween the source electrodes173H/173L/173cand the drain electrodes175H/175L/175c, respectively.

A protective film180may be disposed on the data conductors171,175H,175L, and175cand the exposed semiconductor layers154H,154L, and154c. The protective film180may be an inorganic film or an organic film. The protective film180may have a double-layer structure of a lower inorganic film and an upper organic film in order to protect the semiconductor layers154H,154L, and154c. Further, the protective film180may have a triple-layer structure of a lower inorganic film, an organic film disposed on the lower inorganic film, and another inorganic film disposed on the organic film. Here, as the organic film used in the protective film180, a color filter may be used.

In an exemplary embodiment, for example, a lower protective film180pincluding an inorganic insulating material such as silicon nitride or silicon oxide may be disposed on the data conductors171,175H,175L, and175cand the exposed semiconductor layers154H,154L, and154c.

An organic film may be disposed on the lower protective film180p. Here, a color filter1800may be used as the organic film. The color filter1800vertically extends along the space between the adjacent data lines171. In an exemplary embodiment, the color filter1800may display one of the three primary colors of red, green and blue colors, for example. The color filters1800may be arranged on the data lines such that they overlap with each other.

An upper protective film180qmay be disposed on the lower protective film180pexposed by an opening defined in the color filter1800. The upper protective film180qprevents the color filter1800from being lifted up, prevents the liquid crystal layer300from being contaminated by the organic matter, such as a solvent, inflowing from the color filter1800, thereby preventing the defects such as residual images which may occur during screen driving. In an exemplary embodiment, the upper protective film180qmay include an inorganic insulating material such as silicon nitride or silicon oxide, or an organic material.

The lower protective film180p, the color filter1800, and the upper protective film180qmay be provided with a first contact hole185H and a second contact hole185L through which the end portion of the first drain electrode175H and the end portion of the second drain electrode175L are respectively exposed.

A plurality of pixel electrodes191is disposed on the upper protective film180q. The pixel electrodes191may be connected to the first drain electrode175H and the second drain electrode175L through the first contact hole185H and the second contact hole185L, respectively. Each of the pixel electrodes191may include a transparent conductor such as indium tin oxide (“ITO”) or indium zinc oxide (“IZO”). When a voltage is transmitted to the pixel electrodes191through the first drain electrode175H and the second drain electrode175L to which a data voltage is applied, these pixel electrodes191generate an electric field with the common electrode270disposed in the second panel200, thereby rotating the liquid crystal molecules302in the liquid crystal layer300disposed between the first panel100and the second panel200.

The pixel electrodes191may receive data voltage through the TFTs Q controlled by gate signals. In other words, the first sub-pixel electrode191H and the second sub-pixel electrode191L, shown inFIG. 1, are respectively connected with the first drain electrode175H and the second drain electrode175L through the first contact hole185H and the second contact hole185L, respectively, and may receive data voltage from the first drain electrode175H and the second drain electrode175L.

The pixel electrodes191may be respectively disposed in the pixels PX defined by the gate line121and the data line171.

The pixel electrodes191are separated from each other by the gate line121disposed therebetween to be separately arranged in the upper and lower portions of the pixel region, and thus each of the pixel electrodes191may include the first sub-pixel electrode191H and the second sub-pixel electrode191L, which are neighbored in the column direction.

As such, when the first sub-pixel electrode191H and the second sub-pixel electrode191L are arranged in one pixel PX, a viewing angle may be improved. The pixel electrode191will be described in detail later with reference toFIG. 4.

The second panel200includes a second substrate210, which faces the first substrate110, and a common electrode270. In an exemplary embodiment, the second substrate210may include transparent glass or plastic, and the common electrode270may be disposed on the second substrate210.

In an exemplary embodiment, the light blocking member330and the color filter1800may be disposed on the second panel200. The second substrate210may be selectively provided thereon with a light blocking member, a color filter, an overcoat film, and a second alignment film. In the exemplary embodiment, a color filter and a light blocking member is disposed on the second panel200, similarly to the above-mentioned exemplary embodiment in which a color filter and a light blocking member is disposed on the first panel100.

As such, when the color filter1800and the light blocking member330are disposed on the first substrate110, it is possible to prevent the problem of the misalignment of wirings at the time of using the LCD in curved displays and to prevent the problem of causing the misalignment of liquid crystals at the time of determining the alignment direction with the second alignment film.

Briefly explaining the arrangement relation when a light blocking member, a color filter, an overcoat film, and a second alignment film are selectively disposed on the second substrate210, a color filter of a plurality of colors may be disposed on the second substrate210, and a light blocking member may be disposed at the boundary of the plurality of color filters. The color filter serves as a filter for transmitting the color of a specific wavelength, and the light blocking member, also referred to as a black matrix, may prevent the leakage of light and the color mixture of the color filter.

Further, an overcoat film and a second alignment film may be selectively disposed in the second panel200. The overcoat film may be disposed on the front surface of the second substrate210provided with the color filter and the light blocking member. In an exemplary embodiment, the overcoat film may include an insulating material, and may provide a flat surface. In another exemplary embodiment, the overcoat film may be omitted.

A common electrode270may be disposed on the overcoat film. A second alignment film may be disposed on the common electrode270, which is a vertically aligned film. In another exemplary embodiment, the second alignment film may be omitted. The common electrode270may be disposed on the second substrate210as an entire plate.

Hereinafter, the operation of the LCD configured as described above will be described with reference toFIG. 3. In the LCD according to the exemplary embodiment, one pixel may include a first switching element QH, a second switching element QL, and a third switching element Qc, each of which includes a TFT, and a first liquid crystal capacitor C1and a second liquid crystal capacitor C2, each of which includes a dielectric composed of the liquid crystal layer300.

The sources of the first switching element QH and the second switching element QL, that is, input terminals are connected to the data line DL, the gates thereof, that is, control terminals are connected to the gate line GL, and the gate of the third switching element Qc, that is, a control terminal is connected to the gate line GL.

The contact point CP of the drain of the second switching element QL and the source of the third switching element Qc may be connected to the second sub-pixel electrode191L of the second liquid crystal capacitor C2, and the drain of the first switching element QH, that is, an output terminal may be connected to the first sub-pixel electrode191H of the first liquid crystal capacitor C1. The ends of the first and second liquid crystal capacitors C1and C2may be connected to the common electrode270. The drain of the third switching element Qc, that is, an output terminal is connected to the sustain electrode line131. The second sub-pixel electrode191L is electrically connected to the partial reference line RL through the third switching element Qc.

When a gate-on signal is applied to the gate line GL, the first switching element QH, the second switching element QL, and the third switching element Qc, which are connected to the gate line GL, may be turned on. Therefore, a data voltage applied to the data line DL is applied to the first sub-pixel electrode191H through the first switching element QH. A voltage applied to the second sub-pixel electrode191L may be divided through the third switching element Qc serially connected with the second switching element QL. Therefore, the voltage applied to the second sub-pixel electrode191L may be lower than the voltage applied to the first sub-pixel electrode191H.

Consequently, the voltage charged in the first liquid crystal capacitor C1may be different from the voltage charged in the second liquid crystal capacitor C2. Since the voltage charged in the first liquid crystal capacitor C1and the voltage charged in the second liquid crystal capacitor C2are different from each other, the tilt angles of liquid crystal molecules in the first sub-pixel PXH and the second sub-pixel PXL are different from each other, and thus the brightnesses of the two sub-pixels may be different.

Therefore, when the voltage charged in the first liquid crystal capacitor C1and the voltage charged in the second liquid crystal capacitor C2are appropriately adjusted, the image viewed from the side may be substantially close to the image viewed from the front, and thus it is possible to improve the side visibility of the LCD.

In the illustrated embodiment, in order to differ the voltage charged in the first liquid crystal capacitor C1and the voltage charged in the second liquid crystal capacitor C2from each other, the LCD according to the exemplary embodiment includes the third switching element Qc connected to the second liquid crystal capacitor C2and the partial reference line RL. However, in the case of an LCD according to another exemplary embodiment of the invention, the second liquid crystal capacitor C2may be connected to a step-down capacitor.

Specifically, the LCD according to another exemplary embodiment of the invention includes a first terminal connected to a step-down gate line, a second terminal connected to the second liquid crystal capacitor C2, and a third terminal connected to a step-down capacitor. In the above described LCD, a part of the amount of electric charge charged in the second liquid crystal capacitor C2is charged in the step-down capacitor, and thus a charging voltage between the first liquid crystal capacitor C1and the second liquid crystal capacitor C2may be set differently. Further, in the case of the LCD according to another exemplary embodiment of the invention, the first liquid crystal capacitor C1and the second liquid crystal capacitor C2are respectively connected to different data lines to receive data voltages different from each other, thereby setting the charging voltage between the first liquid crystal capacitor C1and the second liquid crystal capacitor C2differently. In addition, by different various methods, the charging voltage between the first liquid crystal capacitor C1and the second liquid crystal capacitor C2may also be set differently.

Referring toFIG. 4in order to specifically explain the pixel electrode191, the pixel PX may have a substantially rectangular shape, the pixel electrode191may be disposed to cover the pixel PX, and the common electrode270may be integrally disposed on the entire second panel200.

When an electric field is generated in the liquid crystal layer300by providing a potential difference between the pixel electrode191and the common electrode270, liquid crystal molecules302(refer toFIG. 2) may be arranged such that the major axis thereof are aligned in a direction perpendicular to the electric field. The degree of change in polarization of incident light in the liquid crystal layer300may be varied depending on the degree of inclination of the liquid crystal molecules302. This change of polarization appears as the change of transmittance by first and second polarizing plates140and240, and the LCD may display an image through the change of transmittance.

Further, in order to improve the viewing angle of the LCD displaying an image, a plurality of domains may be provided by patterning the pixel electrode191and the common electrode270.

In an exemplary embodiment, for example, the pixel PX may include one pixel electrode191and the common electrode270corresponding to the pixel electrode191. Here, as described above, when the pixel electrode is patterned, the liquid crystal molecules302having average liquid crystal azimuths different from each other may be divided into a plurality of domains having directions different from each other. Hereinafter, the liquid crystal molecules302having an average liquid crystal azimuth are referred to as “average liquid crystal azimuth310”.

As such, the pixel electrode191and protrusions198H and198L may be arranged in the region of the pixel PX divided into the plurality of domains. As described above, the pixel electrode191may include the first sub-pixel electrode191H and the second sub-pixel electrode191L. Hereinafter, for the convenience of explanation, the protrusions198H and198L respectively disposed on the first sub-pixel electrode191H and the second sub-pixel electrode191L are referred to as “a protrusion unit198”, and external bundling electrodes193H and193L are referred to as “an external bundling electrode unit193”.

The protrusion unit198may be disposed along the edge of the region of the pixel PX. The external bundling electrode unit193, which is disposed in parallel to the protrusion unit198, may be disposed in the region of the pixel PX. The external bundling electrode unit193may be disposed to contact the protrusion nit198, or a part of the external bundling electrode unit193may be disposed to overlay the protrusion unit198. Further, a part of the external bundling electrode unit193may be disposed to be overlaid on the protrusion unit198.

In an exemplary embodiment, the protrusion unit198and the external bundling electrode unit193may be disposed on at least one side of the pixel PX when the pixel PX has a rectangular shape, for example. That is, the protrusion unit198and the external bundling electrode unit193may be disposed on at least one side of the pixel PX such that their edges are integrally provided. Further, some of the edges of the protrusion unit198and the external bundling electrode unit193may be integrally provided.

The protrusion unit198and the external bundling electrode unit193may be disposed in at least one of the plurality of domains Da, Db, Dc, and Dd. In the exemplary embodiment, it is shown that the external bundling electrode unit193is disposed in each of the first to forth domains Da, Db, Dc, and Dd in parallel to each of the horizontal/vertical stems192aand192b. However, the invention is not limited thereto.

In an exemplary embodiment, the width of each of the protrusion unit198and the external bundling electrode unit193may be in a range of about 7 micrometers (μm) to about 9 μm, for example. In an exemplary embodiment, the width of the protrusion unit198may be in a range of about 3 μm to about 5 μm, for example.

The protrusion unit198and the external bundling electrode unit193may be disposed such that they are partially overlaid. In order to align the protrusion unit198and the external bundling electrode unit193, a region in each which the protrusion unit198and the external bundling electrode unit193are partially overlaid may be provided. However, as the area of this region decreases, the exposed area of the external bundling electrode unit193increases, thereby improving transmittance.

In an exemplary embodiment, the height of the protrusion unit198taken along a cross sectional direction may be in a range of about 0.5 μm to about 2 μm, for example. When the height of the protrusion unit198is too high, the height thereof becomes equal to that of a spacer because the protrusion unit198overlaps with the cell gaps of the liquid crystal layer300. Therefore, when the height of the protrusion unit198becomes approximately equal to that of the spacer, the fluidity of liquid crystals becomes poor, dark spot defects may occur in the vicinity of the protrusion unit198. Further, when the height of the protrusion unit198is too low, it may be difficult to define a pretilt angle of liquid crystals, the pretilt angle being caused by the surface level difference of the protrusion unit198. Therefore, the height of the protrusion unit198may be in a range of about 0.5 μm to about 2 μm, for example.

As shown inFIG. 4, the pixel electrode191includes the external bundling electrode unit193disposed along the edge of the pixel PX, and a horizontal stem192aand a vertical stem192bwhich are connected to the external bundling electrode unit193and divide the pixel PX into a plurality of domains. Here, the plurality of domains divided by the horizontal stem192aand the vertical stem192bincludes a branch unit194extending to the horizontal stem192aand the vertical stem192b. The branch unit194includes branch electrodes194a,194b,194c, and194dwhich are respectively disposed in the domains.

Further, in the pixel PX, slit patterns195a,195b, and195cconstituting a slit pattern unit195may be disposed between the branch electrodes194a,194b,194c, and194d. Here, each of the slit patterns195is defined by partially removing each of the branch electrodes194a,194b,194c, and194dto expose the insulating film including the protective film180disposed under the pixel electrode191.

For the convenience of explanation, one domain, that is, the first domain Da will be representatively described. A first slit pattern195awhich may separate the respective branch electrodes194a,194b,194c, and194d, a second slit pattern195bwhich contacts the vertical stem192band is disposed in parallel to the horizontal stem192a, and a third slit pattern195cwhich contacts the horizontal stem192aand is disposed in parallel to the vertical stem192bmay be included in the slit pattern unit195. Here, the second slit pattern195band the third slit pattern195care connected to each other. Further, the first, second, and third slit patterns195a,195b, and195cmay be disposed at regular widths.

The second slit pattern195bmay be disposed between the right region of the external bundling electrode unit193and the end of the first branch electrode194ato separate the end of the first branch electrode194afrom the external bundling electrode unit193. In other words, the second slit pattern195bmay be disposed along the upper end of the first branch electrode194a.

The third slit pattern195cmay be disposed between the upper region of the external bundling electrode unit193and the end of the first branch electrode194ato separate the end of the first branch electrode194afrom the external bundling electrode unit193. In other words, the third slit pattern195cmay be disposed along the right end of the first branch electrode194a.

Therefore, due to the arrangement of the second and third slit patterns195band195c, one end of at least one of the branch electrodes194a,194b,194c, and194dmay be disposed to contact the stem unit192, and the other end of at least one of the branch electrodes194a,194b,194c, and194dmay be disposed to contact the second and third slit patterns195band195c. Similarly to the first domain Da, each of the second, third, and fourth domains Db, Dc, and Dd may also be provided with the first, second, and third slit patterns195a,195b, and195c.

As such, one pixel PX may be provided with the protrusion unit198and the pixel electrode191, and the protrusion unit198may be disposed to surround the edge of the pixel electrode191. Further, the pixel electrode191is configured such that the external bundling electrode unit193which contacts the protrusion unit198and are disposed in parallel to the protrusion unit198, the horizontal and vertical stems192aand192bwhich are connected to the external bundling electrode unit193and divide the pixel PX into a plurality of domains, and the branch unit194extending to the horizontal stem192aand the vertical stem192bto be connected with the external bundling electrode unit193are integrally provided. Therefore, the integrally provided external bundling electrode unit193, horizontal and vertical stems192aand192b, and branch electrodes194a,194b,194c,194dmay receive the same voltage. Moreover, a plurality of domains may be provided by the horizontal and vertical stems192aand192bwhile receiving the same voltage.

Therefore, the pixel PX may include four domains, in which the horizontal stem192aand vertical stem192bof the pixel electrode191are defined as boundaries, that is, the first to fourth domains. In an exemplary embodiment, the width of the stem unit192may be about 2 μm to 5 μm, for example, and when necessary, the width thereof may be adjusted in order to improve the control of liquid crystals.

In other words, in the region provided with the stem unit192, aperture ratio may be reduced because liquid crystal molecules302are not laid down. When the width of the stem unit192greatly increases, aperture ratio and transmittance may be reduced due to the increase in the fringe field at the boundary between the first to fourth domains Da, Db, Dc, and Dd, so that it is possible to prevent the transmittance of the pixel from being reduced by adjusting the width of the stem unit192. In the intersection region of the horizontal and vertical stems192aand192b, unlikeFIG. 4, the electrode area of the intersection region may be adjusted.

The pixel PX is divided by the horizontal and vertical stems192aand192bto define the first to fourth domains Da, Db, Dc, and Dd. The branch unit194extending from each of the horizontal and vertical stems192aand192bmay be disposed in the pixel PX. Further, the branch unit194may include the plurality of first to fourth branch electrodes194a,194b,194c, and194dwhich are respectively disposed in the first to fourth domains Da, Db, Dc, and Dd. Hereinafter, the first to fourth branch electrodes194a,194b,194c, and194dare collectively referred to as “branch electrodes194a,194b,194c, and194d” for convenience.

In the branch unit194, the first branch electrode194amay be disposed in the first domain Da to be obliquely extended from the horizontal and vertical stems192aand192bin the upper right direction, and the second branch electrode194bmay be disposed in the second domain Db to be obliquely extended from the horizontal and vertical stems192aand192bin the upper left direction. Further, the third branch electrode194cmay be disposed in the third domain Dc to be obliquely extended from the horizontal and vertical stems192aand192bin the lower left direction, and the fourth branch electrode194dmay be disposed in the fourth domain Dd to be obliquely extended from the horizontal and vertical stems192aand192bin the lower right direction.

In an exemplary embodiment, the first and second branch electrodes194aand194bmay be disposed at angles of about 45 degrees (°) and about 135° with reference to the horizontal stem192a, respectively. In an exemplary embodiment, the third and fourth branch electrodes194cand194dmay be disposed at angles of about 225° and about 315° with reference to the horizontal stem192a, respectively. The branch electrodes194ato194dof the adjacent two domains Da and Dd may be disposed in a direction perpendicular to each other.

In other words, the branch electrodes194a,194b,194c, and194dmay be arranged such that, for example, in the first domain Da, the extension direction of the first branch electrode194is disposed at an angle of about 30° to about 60° with reference to the polarization axis of the polarizing plate140or240, for example.

As such, when the branch unit194extends from any one of the horizontal and vertical stems192aand192b, texture is reduced and transmittance is improved with the improvement of control of liquid crystals. Here, the branch electrodes194a,194b,194c, and194dmay be arranged to be symmetrical to each other in each domain. That is, the branch electrodes194a,194b,194c, and194dmay be arranged such that the ends of the branch electrodes194a,194b,194c, and194dcorrespond to the ends of the branch electrodes194a,194b,194c, and194dof the adjacent pixel PX.

The branch electrodes194a,194b,194c, and194dmay be asymmetrically extended and arranged. That is, the branch electrodes194a,194b,194c, and194dmay be arranged such that the ends of the branch electrodes194a,194b,194c, and194dcorrespond to the slit pattern unit195of the adjacent pixel PX. Here, when the branch electrodes194a,194b,194c, and194dare asymmetrically extended and arranged, the performance of control of liquid crystals may be effectively improved. That is, the branch electrodes194a,194b,194c, and194ddisposed in the domain and the slit pattern unit195in the domain adjacent to this domain may be alternately arranged.

As such, when the protrusion unit198is disposed in the edge region of the pixel PX, and the pixel electrode191, including the external bundling electrode unit193disposed in parallel to the protrusion unit198, the horizontal and vertical stems192aand192bconnected to the external bundling electrode unit193and dividing the pixel PX into a plurality of domains, and the branch unit194extending in a diagonal direction with reference to the intersection of the horizontal and vertical stems192aand192b, is disposed in the pixel PX, the liquid crystal molecules302having the average liquid crystal azimuth310capable of exhibiting the maximum transmittance may be provided.

Here, the sides of the first to fourth branch electrodes194a,194b,194c, and194ddistort an electric field to define horizontal components that determine the inclination direction of the liquid crystal molecules302. The horizontal components of the electric field may arrange the liquid crystal molecules302in a direction parallel to the length direction of the first to fourth branch electrodes194a,194b,194c, and194dby the behavior of the liquid crystal molecules302. Therefore, as described inFIGS. 1 to 4, the liquid crystal molecules302may be inclined in a direction parallel to the length direction of the first to fourth branch electrodes194a,194b,194c, and194d. Since one pixel electrode191includes four domains Da to Dd, in which length directions of the branch electrodes194a,194b,194c, and194dare different from each other, the liquid crystal molecules302are inclined in approximately four directions, and the four domains Da to Dd, in which the alignment directions of liquid crystal molecules302are different, may be provided in one sub-pixel.

Further, the liquid crystal molecules302irregularly arranged at the edge of the domain may be arranged in a direction similar to the average liquid crystal azimuth310through the second and third slit patterns195band195c, the protrusion unit198and the external bundling electrode unit193.

The branch electrodes194ato194dand the slit patterns195a,195b, and195cmay be arranged at regular widths. Further, the width of the external bundling electrode unit193may be the same as that of each of the branch electrodes194ato194d. In an exemplary embodiment, the width of the external bundling electrode unit193may be in a range of about 1 μm to about 5 μm, for example. Specifically, the width of the external bundling electrode unit193may be in a range of about 2 μm to about 4 μm, for example.

As such, since the intervals between the external bundling electrode unit193and the branch electrodes194ato194dare similar to each other, the electric field forces between the branch electrodes194ato194dare similar to each other. Therefore, it is possible to prevent the liquid crystal molecules302from being biased in any one direction.

In an exemplary embodiment, the pitches of the branch electrodes194ato194dand the first slit pattern195amay be in a range of about 4 μm to about 8 μm, for example. More specifically, the pitches of the branch electrodes194ato194dand the first slit pattern195amay be in a range of about 5 μm to about 7 μm, for example. In an exemplary embodiment, the widths of the second and third slit patterns195band195cand the external bundling electrode unit193may be in a range of about 4 μm to about 8 μm, and more specifically about 5 μm to about 7 μm, for example.

In an exemplary embodiment, the lengths of the branch electrodes194ato194d, that is, the lengths of the branch electrodes194ato194d, which extend from the intersection region of the stem unit192to the corner region of the pixel PX, may be in a range of about 25 μm to about 30 μm, for example, in which liquid crystal control is possible. Specifically, the lengths from the ends of the branch electrodes194ato194dto the corner region of the pixel PX may be in a range of about 26 μm to about 28 μm, for example.

When the liquid crystal molecules302in the above described domains Da, Db, Dc, and Dd have an average liquid crystal azimuth310, which is an average alignment direction of the liquid crystal molecules302, the average liquid crystal azimuth310may be inclined in a direction consisting of the sum of a vector caused by the electric field in each of the corresponding domains Da, Db, Dc, and Dd and a vector caused by the collision of liquid crystals. That is, the liquid crystal molecules302may define an azimuth similar to the extending direction of the branch electrodes194a,194b,194c, and194d. The liquid crystal molecules302in each of the domains Da, Db, Dc, and Dd may be aligned to have the average liquid crystal azimuth in the direction represented by arrows a, b, c, and d, as seen in plan view.

Specifically, the liquid crystal molecules302may be arranged in a direction approximately parallel to the direction from four points at which the edges of the pixel electrode, extending in the different directions, meet each other toward the center of the horizontal and vertical stems192aand192b. Therefore, the liquid crystal molecules302are arranged in a direction similar to the direction in which the branch electrodes194ato194dare extended by the influence of an electric field in each of the domains Da, Db, Dc, and Dd, and the number of the tilting directions of the liquid crystal molecules302in each region of an electric field forming electrode may be four.

As such, the liquid crystal molecules302may define the average liquid crystal azimuth in a direction similar to the extending direction of the branch electrodes194a,194b,194c, and194din each of the domains Da, Db, Dc, and Dd.

Therefore, in the illustrated exemplary embodiment of the invention, since the branch electrodes194ato194dof one pixel PX extend in four longitudinal directions, the liquid crystal molecules302may also be tilted in four directions. As such, when the tilting direction of the liquid crystal molecules302becomes various, the transmittance and reference viewing angle of the LCD may be increased.

FIG. 5is a plan view showing a liquid crystal behavior of the LCD device according to an exemplary embodiment of the invention,FIG. 6is an enlarged plan view of one pixel according to another exemplary embodiment of the invention, andFIG. 7is a cross-sectional view taken along line II-II ofFIG. 5.

Here, it is shown inFIGS. 5 to 7that an LCD includes one pixel PX, but the LCD may include a plurality of pixels repeatedly arranged in rows and columns. Here, the behavior of liquid crystals will be described by reference toFIGS. 1 to 4, and one pixel will be representatively described for example.

First, the LCD according to the embodiment of invention is configured such that, when a voltage is applied between the pixel electrode191and the common electrode270, the behavior of the liquid crystal molecules302is changed, and the refractive index of liquid crystals is changed, thereby realizing gradation.

The LCD according to the embodiment of invention may exhibit high contrast ratio due to excellent dark characteristics, whereas the transmittance of liquid crystals depending on the behavior of the liquid crystal molecules302may be greatly changed depending on a viewing angle because negative liquid crystals are used. That is, the LCD is vulnerable to a viewing angle because the transmittance of liquid crystals is changed depending on the viewing angle.

In order to solve the problem with the view angle of the LCD, as described inFIGS. 1 and 2, an electrode is provided in each of the first panel100and the second panel200to define a plurality of domains changing the behavior direction of the liquid crystal molecules302. Here, the electrode may be a pixel electrode191or a common electrode270.

As such, when the plurality of domains Da to Dd is provided, the difference in refractive index of liquid crystals depending on the direction of a viewing angle may be minimized, thereby improving visibility. However, although the difference in refractive index of liquid crystals depending on the direction of a viewing angle is minimized using a structure of the plurality of domains Da to Dd, there may be still a problem that a gradation curve is distorted at the lateral side of the LCD.

The reason for this is because there may be a problem that the structure of the plurality of domains Da to Dd deteriorates light efficiency due to the disclination line located at the lateral side of the pixel PX. The reason for this is because, at the time of implementing a bright state and a dark state, some of the liquid crystal molecules302are behaved in a direction matching the polarization axis of the polarizing plate140or240, and thus disclination lines are generated.

In order to solve the above problems, as described inFIGS. 1 and 2, the distortion of a gradation curve in the low gradation region (dark state) and the high gradation region (bright state) may be reduced by changing the electrode pattern191. Further, the difference in transmittance at the time of low gradation and high gradation may be reduced to minimize the distortion of a gradation curve, thereby improving visibility.

Hereinafter, the behavior of liquid crystal molecules will be described in detail. InFIGS. 5 to 7, the behavior of liquid crystal molecules will be described with respect to one pixel.

InFIG. 5, an external bundling electrode193including external bundling electrodes193H and193L (refer toFIG. 1) is disposed at both lateral sides and upper and lower sides of a pixel PX. InFIG. 6, an external bundling electrode193including external bundling electrodes193H and193L is disposed at both lateral sides of the pixel PX. InFIG. 7, in order to express the behavior of liquid crystals, the cross section of the corner region of the pixel PX is shown.

Explaining the behavior of the liquid crystal molecules302with reference toFIGS. 5 to 7, a data voltage is applied to the pixel electrode191, and a common voltage is applied to the common electrode270, thereby generating an electric field in the liquid crystal layer300between the two electric field generating electrodes.

In response to the electric field, the liquid crystal molecules302of the liquid crystal layer300may be defined by fringe fields F1to F4generated by the slit pattern unit195of the common electrode270and the pixel electrode191. Hereinafter, the horizontal electric field component in the first direction, which provides a behavior of the liquid crystal molecules302to the fringe field, is referred to as “first horizontal electric field F1”, the horizontal electric field component in the second direction is referred to as “second horizontal electric field F2”, the horizontal electric field component in the third direction is referred to as “third horizontal electric field F3”, and the horizontal electric field component in the fourth direction is referred to as “fourth horizontal electric field F4”.

Here, the fringe field may include a first director301aof the liquid crystal molecules302(refer toFIG. 2) by the first horizontal electric field F1which is provided in a direction from two edge sides of the pixel electrode191, that is, the upper sides of the first domain Da and the second domain Db to the inside of the pixel PX, and a second director301bof the liquid crystal molecules302by the second horizontal electric field F2which is provided in a direction from the right sides of the first domain Da and the fourth domain Dd to the inside of the pixel PX.

Further, the fringe field may include a third director301cof the liquid crystal molecules302by the third horizontal electric field F3which is provided in a direction from two edge sides of the pixel electrode191, that is, the lower sides of the third domain Dc and the fourth domain Dd to the inside of the pixel PX, and a fourth director301dof the liquid crystal molecules302by the fourth horizontal electric field F4which is provided in a direction from the left sides of the second domain Db and the third domain Dc to the inside of the pixel PX.

As such, the first to fourth directors301ato301dof the liquid crystal molecules302by the first to fourth horizontal electric fields F1to F4which are provided in the inner direction of the pixel PX may be inclined approximately parallel to the polarization axis of each of the polarizing plates140and240. That is, the liquid crystal molecules302in one pixel PX may be inclined in four directions.

More specifically, each of the first and second directors301aand301bof the liquid crystal molecules302at the region adjacent to the edge of the pixel electrode191in one pixel PX may be disposed perpendicular to the edge of the pixel electrode191. Like this, the directors301a,301b,301c, and301dof the liquid crystal molecules302by the fringe field generated at the edge of the pixel electrode191in one pixel PX may be primarily determined. Here, due to the directors301a,301b,301c, and301dof the liquid crystal molecules302by the fringe field, a force for providing the behavior of the liquid crystal molecules302in a direction to the inside of the pixel PX may be provided by the protrusions198.

Like this, due to the primary behavior of the liquid crystal molecules302in a direction approximately parallel to the polarization axis of each of the polarizing plates140and240by the fringe fields F1to F4provided by electrodes, these liquid crystal molecules302may be provided into the first to fourth directors301a,301b,301c, and301d.

The liquid crystal molecules302behaved by the first to fourth directors301a,301b,301c, and301dmay be secondarily arranged in a direction in which the liquid crystal molecules302meet each other in the pixel PX to minimize the distortion thereof. Here, the secondary arrangement direction of the first to fourth directors301a,301b,301c, and301dmay be a direction of the sum of vectors of these directors.

Therefore, due to the behavior of the liquid crystal molecules302in the direction of the sum of vectors of the directors, the average liquid crystal azimuth310may be provided in a direction similar to the extending direction of the branch electrodes194a,194b,194c, and194din each of the domains Da, Db, Dc, and Dd. That is, the liquid crystal molecules302may be arranged in each of the domains Da, Db, Dc, and Dd in the pixel PX to have average liquid crystal azimuths310different from each other.

Further, the first to fourth directors301a,301b,301c, and301dmay be also provided at the branch electrodes194a,194b,194c, and194ddisposed between the first, second, and third slit patterns195a,195b, and195c.

Specifically, the sides of the branch electrodes194ato194dmake horizontal components perpendicular to the sides thereof by distorting an electric field, and the tilt direction of the liquid crystal molecules302may be determined by the fringe fields F1to F4. Therefore, the liquid crystal molecules302are first inclined in a direction perpendicular to the sides of the branch electrodes194ato194d.

Here, since the horizontal components of the electric field by the adjacent branch electrodes194ato194dare arranged in a direction opposite to each other, and the intervals between branch electrodes194aare narrow, the liquid crystal molecules to be inclined in a direction opposite to each other may be inclined altogether in a direction parallel to the longitudinal direction of the branch electrodes194ato194d.

Therefore, in the embodiment of the invention, the liquid crystal molecules302may be inclined in two stages in the length direction of the branch electrodes194ato194d. Moreover, when the liquid crystal molecules302are secondarily arranged to dispose the protrusions198at the edge of the pixel PX, the liquid crystal molecules302are pre-inclined in a direction parallel to the length direction of the branch electrodes194ato194d, and thus the liquid crystal molecules302may be arranged in a direction parallel to the length direction of the branch electrodes194ato194d.

As such, since the liquid crystal molecules302may be inclined in the direction of each of the first to fourth directors301a,301b,301c, and301dby the influence of the fringe fields F1to F4by disposing the slit pattern unit195in the pixel PX, it is possible to improve the response speed of the LCD.

As described above, due to the behavior of the liquid crystal molecules302, the average liquid crystal azimuths in the domains Da, Db, Dc, and Dd may be made different, respectively.

In the first domain Da of the pixel PX, the director of the liquid crystal molecules302is obliquely disposed in the upper right direction of the horizontal stem192ato define an average liquid crystal azimuth310in the direction of arrow a.

In the second domain Db of the pixel PX, the directors of the liquid crystal molecules302is obliquely disposed in the upper left direction of the horizontal stem192ato define an average liquid crystal azimuth310in the direction of arrow b.

In the third domain Dc of the pixel PX, the directors of the liquid crystal molecules302is obliquely disposed in the lower left direction of the horizontal stem192ato define an average liquid crystal azimuth310in the direction of arrow c.

In the fourth domain Dd of the pixel PX, the directors of the liquid crystal molecules302is obliquely disposed in the lower right direction of the horizontal stem192ato define an average liquid crystal azimuth310in the direction of arrow d.

Therefore, since the arrangement of the liquid crystals may be controlled such that the arrangement directions thereof are different from each other along the longitudinal direction of the branch electrodes194ato194ddisposed in a plurality of domains, it is possible to improve the lateral visibility of the LCD of the invention.

Referring toFIG. 6, in one pixel, the region in which the branch unit194adjacent to the intersection of the stem unit192is disposed is defined as a first region X. In the first region X, the liquid crystal molecules302may be arranged in the direction of the average liquid crystal azimuth310similar to the extending direction of the branch electrodes194a,194b,194c,194dby the force of the fringe fields F1to F4and the collision of the liquid crystal molecules302.

The upper edge region of the pixel PX, which is spaced apart from the stem unit192, is defined as a second region Y, and the right edge region of the pixel PX is defined as a third region Z. InFIG. 6, the region in which the external bundling electrode unit193and the protrusion unit198are disposed in the pixel electrode191is defined as the third region Z. The region in which the external bundling electrode unit193or the protrusion unit198is not disposed in the pixel electrode191is defined as the second region Y.

Since the protrusion unit198provided at the edge of the pixel PX does not exist in the second region Y, a fifth horizontal electric field component F5applied in the direction to outside of the pixel PX may be provided.

As such, in the second region Y, due to the fifth horizontal electric field component F5, a fifth director301emay be provided. Therefore, when the fifth director301ebehaved by the fifth horizontal electric field component F5respectively collides with the second director301bbehaved by the second horizontal electric field component F2and the fourth director301dbehaved by the fourth horizontal electric field component F4, the liquid crystal molecules302in the second region Y may be liquid crystal molecules302having a liquid crystal azimuth different from the average liquid crystal azimuth310. The liquid crystal molecules302having the above liquid crystal azimuth are referred to as liquid crystal molecules302having a fifth liquid crystal azimuth310-1.

As described above, due to the liquid crystal molecules302having the fifth liquid crystal azimuth310-1different from the average liquid crystal azimuth310, in the second region, the fifth liquid crystal azimuth310-1is away from the polarization axis by more than about 45° deteriorating transmittance, and thus texture may occur.

As such, in the second region Y, the vector capable of secondarily behaving the liquid crystal molecules302having the second director301b, that is, the first horizontal electric field F1is weak, or the fifth horizontal electric field F5opposite to the first horizontal electric field F1is provided, so that liquid crystal molecules302lying in parallel to the horizontal stem192amay be provided. Moreover, due to the component of the fifth horizontal electric field F5, liquid crystal molecules302behaving from acute angle to obtuse angle may be provided.

Therefore, among the liquid crystal molecules302behaved by the fringe fields F1to F4, some of the liquid crystal molecules302disposed in the second region Y may be arranged in a direction approximately parallel to the polarization axis of the polarizing plate140or240or may have the fifth liquid crystal azimuth301-1from acute angle to obtuse angle.

The LCD may exhibit the maximum transmittance when the average liquid crystal azimuth310is designed to be tilted about 45° with reference to the polarization axis of the polarizing plate140or240at the time of applying a voltage to the first and second panels100and200.

However, as described above, in the second region Y of the pixel PX, in which the protrusion unit198is not disposed, the fifth director301ealigned in a direction approximately parallel to the polarization axis may be provided, or the fifth liquid crystal azimuth310-1from acute angle to obtuse angle may be provided. As such, in the second region Y of the pixel PX, due to the liquid crystal molecules302lying in a direction similar to the polarization axis of the polarizing plate140or240, the transmittance of the LCD may be deteriorated. That is, in the second region Y, the angle of the liquid crystal molecules302is away from the polarization axis of the polarizing plate140or240by more than about 45°, and thus the transmittance of the LCD may be deteriorated.

In the third region Z in which the external bundling electrode unit193and the protrusion unit198are arranged, the protrusion unit198is disposed at the edge region of the pixel PX, and thus the pretilt angle of the liquid crystal molecules302in the third region Z may be provided.

In other words, due to the pretilt angle provided by the protrusion unit198, the force of boosting the liquid crystal molecules302is greatly increased even when the fifth horizontal electric field F5, which is aligned in a direction opposite to the first horizontal electric field F1in the third region Z, is provided. Therefore, in the third region Z, the liquid crystal molecules302arranged in a direction similar to the average liquid crystal azimuth310may be provided.

Therefore, the protrusion unit198may provide a force of arranging the liquid crystal molecules302in a direction similar to the average liquid crystal azimuth310by forming a pretilt angle. Further, the second slit pattern195band the third slit pattern195cmay minimize the formation of the fifth director301ein the second region Y by weakening the electric field for defining a director such as the fifth horizontal electric field F5.

Therefore, in the edge region of the pixel PX, that is, the third region Z, the liquid crystal molecules302may be arranged in the direction of a pretilt angle, and thus the liquid crystal molecules302may be arranged relatively close to the average alignment direction of the liquid crystal molecules302in each of the domains Da to Dd, that is, the average liquid crystal azimuth310. Therefore, it is possible to minimize the irregular arrangement of the liquid crystal molecules302occurring in the second region Y which is an edge region of the pixel PX.

As described above, in the LCD, the protrusion unit198is disposed along the edge of the pixel PX to arrange the liquid crystal molecules302in the direction of the average liquid crystal azimuth310, thereby improving the transmittance and lateral viewing angle of the third region Z. Moreover, it is possible to improve response speed by reducing the area of the pixel electrode191.

FIGS. 8 and 9are photographs showing the transmittance of pixels according to Examples of the invention,FIGS. 10 and 11are photographs showing the transmittance of pixels according to Examples and Comparative Examples of the invention, andFIG. 12is a graph showing the transmittance of pixels according to Examples and Comparative Examples of the invention.

Referring toFIGS. 8 to 11, when the protrusion unit198is disposed at the edge region of the pixel PX, the liquid crystal molecules302has a pretilt angle in the direction from the edge of the pixel PX to the inside of the pixel PX, so that it is possible to minimize the horizontal electric field component that irregularly arranges the liquid crystal molecules302and to allow the liquid crystal molecules302to have the average liquid crystal azimuth310. That is, the liquid crystal molecules302having the average liquid crystal azimuth310may be arranged by controlling the sum of a vector caused by an electric field determining the azimuth of the liquid crystal molecules302and a vector caused by the collision of the liquid crystal molecules302, that is, by controlling the components of the two vectors.

Therefore, when the protrusion unit198is disposed at the edge region of the pixel PX, a vector capable of secondarily arranging the liquid crystal molecules302adjacent to the edge of the pixel electrode191is provided, and thus it is possible to prevent the liquid crystal molecules302adjacent to the edge of the pixel electrode191from being inclined in a direction similar to the polarization axis. That is, it is possible to prevent the deterioration of display quality occurring when the liquid crystal molecules302are arranged in a direction parallel to the polarization axis in the edge region of the pixel electrode191, that is, the second and third regions X and Y.

First,FIG. 8shows photographs of planes of a pixel according to an exemplary embodiment of the invention when the response speed is about 30 milliseconds (ms), andFIG. 9shows photographs of planes of a pixel according to an exemplary embodiment of the invention when the response speed is about 300 ms.

InFIGS. 8 and 9, (a) is a photograph showing the plane of a pixel when the external bundling electrode unit193and the protrusion unit198overlap each other by about 0.5 μm, (b) is a photograph showing the plane of a pixel when the external bundling electrode unit193and the protrusion unit198overlap each other by about 1.5 μm, and (c) is a photograph showing the plane of a pixel when the external bundling electrode unit193and the protrusion unit198overlap each other by about 2.5 μm.

FIGS. 10 and 11show photographs imaged under the same conditions as inFIGS. 8 and 9, but Comparative Examples are photographs of a pixel having the protrusion unit198and the branch unit194. That is, Comparative Examples are photographs of a pixel in which the external bundling electrode unit193is not disposed between the branch unit194and the protrusion198. InFIGS. 10 and 11, (d) is a photograph showing the plane of a pixel when the external bundling electrode unit193and the end of the branch unit194overlap each other by about 0.5 μm, (e) is a photograph showing the plane of a pixel when the external bundling electrode unit193and the end of the branch unit194overlap each other by about 1.5 μm, and (f) is a photograph showing the plane of a pixel when the external bundling electrode unit193and the end of the branch unit194overlap each other by about 2.5 μm.

Here, based on Reference Example in which the external bundling electrode unit193and the protrusion unit198are not disposed and only the stem unit192and the branch unit194are disposed in the pixel electrode191and in which transmittance is about 100 percent (%), Examples and Comparative Examples are compared.

Referring toFIG. 12, (a) when the external bundling electrode unit193and the protrusion unit198overlap each other by about 0.5 μm, the transmittance is about 103.6%, and (d) when the external bundling electrode unit193and the end of the branch unit194overlap each other by about 0.5 μm, the transmittance is about 94.8%.

As such, when the overlapping area of the protrusion unit198and the external bundling electrode unit193is small, it is determined that the exposed area of the external bundling electrode unit193increases, so as to increase the transmittance by about 3.6%. Thus, when the protrusion unit198and the external bundling electrode unit193are disposed in one pixel PX, it is possible to increase the number of the liquid crystal molecules302behaving in the edge region of the pixel PX. That is, it is determined that the transmittance in the edge region of the pixel PX is improved by increasing the number of the liquid crystal molecules302having the average liquid crystal azimuth in the edge region of the pixel PX.

In the case of (d) ofFIG. 12, it is seen that the transmittance is further deteriorated by about 5.2% compared to Reference Example. The reason for this is determined that the liquid crystal molecules302behaving in a region corresponding to the region of the external bundling electrode unit193do not exist, and the physical pretilting is provided by the protrusion unit198, so that the number of the liquid crystal molecules302behaving in a direction of about 0° or about 90° increases, so as to deteriorate the transmittance. Here, the liquid crystal molecules302behaving in a direction of about 0° or about 90° become a factor of causing the deterioration of transmittance because this angle is a similar angle to the polarization axis. Moreover, since the external bundling electrode unit is not disposed at the edge of the pixel PX, a horizontal electric field component may not be generated in the edge region of the pixel PX.

Further, referring toFIG. 12, (b) when the external bundling electrode unit193and the protrusion unit198overlap each other by about 1.5 μm, the transmittance is about 100.4%, and (e) when the external bundling electrode unit193and the end of the branch unit194overlap each other by about 1.5 μm, the transmittance is about 89.8%.

As such, when the overlapping area of the protrusion unit198and the external bundling electrode unit193is larger than that in the case of (a), it is determined that the exposed area of the external bundling electrode unit183increases, so as to increase the transmittance by about 0.4%.

In the case of (e) ofFIG. 12, it is seen that the transmittance is further deteriorated by about 10.2% compared to Reference Example. The reason for this is determined that the liquid crystal molecules302behaving in a region corresponding to the region of the external bundling electrode unit193do not exist, and the physical pretilting is provided by the protrusion unit198, so that the number of the liquid crystal molecules302behaving in a direction of about 0° or about 90° increases and the overlapping area of the protrusion unit198and the branch unit194increases, so as to further deteriorate the transmittance.

Further, referring toFIG. 12, (c) when the external bundling electrode unit193and the protrusion unit198overlap each other by about 2.5 μm, the transmittance is about 87.9%, and (f) when the external bundling electrode unit193and the end of the branch unit194overlap each other by about 2.5 μm, the transmittance is about 84.5%.

As such, when the overlapping area of the protrusion unit198and the external bundling electrode unit193is larger than that in the case of (b), it is determined that the exposed area of the external bundling electrode unit183increases, so as to increase the transmittance by about 12.1%.

In the case of (f) ofFIG. 12, it is seen that the transmittance is further deteriorated by about 15.2% compared to Reference Example. The reason for this is determined that the liquid crystal molecules302behaving in a region corresponding to the region of the external bundling electrode unit193do not exist, and the physical pretilting is provided by the protrusion unit198, so that the number of the liquid crystal molecules302behaving in a direction of about 0° or about 90° increases and the overlapping area of the protrusion unit198and the branch unit194increases, so as to further deteriorate the transmittance.

In conclusion, as shown in Example (a) ofFIG. 12, it is seen that the transmittance is increased by allowing the external bundling electrode unit193and the second and third slit patterns195band195cto control the behavior of the liquid crystal molecules302disposed in the edge region of the pixel PX.

As described above, when the external bundling electrode unit193and the protrusion unit are disposed at the edge of one pixel PX, the possibility of forming the liquid crystal molecules302having the average liquid crystal azimuth310increases, thereby improving the transmittance of the LCD. Further, in the LCD according to an exemplary embodiment of the invention, the transmittance thereof may be improved by increasing the exposed area of the pixel electrode191in the region in which the transmittance is deteriorated, and the response speed thereof may be improved by arranging the second and third slit patterns195band195cto decrease the entire area of the pixel electrode191.

FIG. 13is a plan view showing a pixel of the LCD according to still another exemplary embodiment of the invention,FIG. 14is a photograph showing the plane of the pixel ofFIG. 13, andFIGS. 15 to 17are plan views showing pixels of the LCD according to still another exemplary embodiment of the invention.

First, briefly explaining the LCD of the invention, first, one pixel PX may be provided with the protrusion unit198and the pixel electrode191(refer toFIG. 1), and the protrusion unit198may be disposed to surround the edge of the pixel electrode191. Further, the pixel electrode191is configured such that the external bundling electrode unit193which contacts the protrusion unit198and is disposed in parallel to the protrusion unit198, the horizontal and vertical stems192aand192bwhich are connected to the external bundling electrode unit193and divide the pixel PX into a plurality of domains, and the branch unit194extending to the horizontal stem192aand the vertical stem192bto be connected with the external bundling electrode unit193are integrally provided.

The branch unit194is provided with a plurality of branch electrodes194a,194b,194c, and194d, and the branch electrodes194a,194b,194c, and194dmay be spaced apart from each other by the first slit pattern195a.

The first slit pattern195amay be defined by removing the adjacent electrodes194a,194b,194c, and194dto expose an insulating layer including a protective layer disposed under the pixel electrode191.

The second slit pattern195bis disposed between the right and left regions of the external bundling electrode unit193and the ends of the branch electrodes194a,194b,194c, and194dto space the external bundling electrode unit193apart from the ends of the branch electrodes194a,194b,194c, and194d. In other words, the second slit pattern195bmay be disposed along the upper or lower ends of the branch electrodes194a,194b,194c, and194d.

The third slit pattern195cis disposed between the upper and lower regions of the external bundling electrode unit193and the ends of the branch electrodes194a,194b,194c, and194dto space the external bundling electrode unit193apart from the ends of the branch electrodes194a,194b,194c, and194d. In other words, the third slit pattern195cmay be disposed along the right or left ends of the branch electrodes194a,194b,194c, and194d.

In the exemplary embodiment, the fourth slit195dmay further be disposed at each of the corners of the pixel PX. The fourth slit195dmay be disposed at each of the corners thereof to have a symmetric or asymmetric area.

In the exemplary embodiment, the fourth slit pattern195dmay be disposed such that the area of right upper corner region of the pixel PX is the same as that of left lower corner region of the pixel PX, and the area of left upper corner region of the pixel PX is the same as that of right lower corner region of the pixel PX.

As such, the fourth slit195dis further disposed at each of the corners of the pixel PX to minimize the irregular arrangement of the liquid crystal molecules302occurring at the corner region of the pixel PX, so as to prevent the deterioration of transmittance at the corner region thereof.

Referring toFIG. 15, first and second sub-pixel electrodes191H and191L may be disposed in first and second sub-pixel regions PXH and PXL, respectively. Hereinafter, for the convenience of explanation, the first and second sub-pixel regions PXH and PXL are expressed by a sub-pixel PX unit region, and the first and second sub-pixel electrodes191H and191L are expressed by a sub-pixel electrode unit191.

A plurality of sub-pixel electrode units191is disposed in the sub-pixel PX unit region, and the sub-pixel electrode units191may be spaced apart from each other with an intermediate unit196disposed therebetween. A connecting electrode199is provided in the intermediate unit196to connect the adjacent sub-pixel electrode units to each other, thereby receiving the same voltage. The intermediate unit196may include a horizontal intermediate portion196aprovided in the horizontal direction of the sub-pixel PX unit region and a vertical intermediate portion196bprovided in the vertical direction of the sub-pixel PX unit region. Further, a peripheral intermediate unit for adjusting the interval between the gate line121and the data line171disposed along the edge of the sub-pixel PX unit region may be provided.

A protrusion unit198may be disposed in the intermediate unit196for spacing the sub-pixel electrode units191. That is, the protrusion unit198may be disposed on the horizontal and vertical intermediate portions196aand196b, and may also be disposed on the peripheral intermediate unit disposed along the edge of the sub-pixel PX unit region. The connecting electrode199for connecting the sub-pixel electrode units191to each other through the protrusion unit198disposed on the horizontal and vertical intermediate portions196aand196bmay be disposed under the protrusion unit198.

As such, when the protrusion unit198is disposed at the edge of the sub-pixel PX unit region, an electric field proceeding into the sub-pixel PX unit region may be provided. Further, when the external bundling electrode unit193and the second and third slit patterns195band195care disposed in the sub-pixel PX unit region adjacent to the protrusion unit198, a vector capable of secondarily arranging the liquid crystal molecules302disposed in the sub-pixel PX unit region adjacent to the protrusion unit198may be provided.

Therefore, the irregularly arranged liquid crystal molecules302may be arranged in the direction of the average liquid crystal azimuth by behaving the liquid crystal molecules302at the edge of the sub-pixel PX unit region. Accordingly, the transmittance at the edge of the sub-pixel PX unit region is improved, and thus the transmittance of the entire pixel PX may be improved.

Referring toFIG. 16, based on each of sub-pixel electrode units191, the protrusion unit198may be disposed at a part of the edge of each of the sub-pixel electrode unit191.

Therefore, the protrusion units198may be disposed in the edge region of the sub-pixel PX unit region one by one. That is, other protrusions198a,198b,198c, and198d, which are spaced apart from the protrusion unit198, may be disposed in a region in which the peripheral intermediate unit is provided. Further, the protrusion unit198may be arranged to be connected to each other in the horizontal and vertical intermediate portions196aand196b.

For the convenience of explanation, the protrusion unit198disposed at the right side of the sub-pixel electrode unit191is defined as a first protrusion unit198a, the protrusion unit198disposed at the upper side of the sub-pixel electrode unit191is defined as a second protrusion unit198b, the protrusion unit198disposed at the left side of the sub-pixel electrode unit191is defined as a third protrusion unit198c, and the protrusion unit198disposed at the lower side of the sub-pixel electrode unit191is defined as a fourth protrusion unit198d.

Further, among the sub-pixel electrode units191disposed in the sub-pixel PX unit region, the sub-pixel electrode unit191disposed at right upper side of the sub-pixel PX unit region is defined as a first sub-pixel electrode unit PX1, the sub-pixel electrode unit191disposed at left upper side of the sub-pixel PX unit region is defined as a second sub-pixel electrode unit PX2, the sub-pixel electrode unit191disposed at left lower side of the sub-pixel PX unit region is defined as a third sub-pixel electrode unit PX3, and the sub-pixel electrode unit191disposed at right lower side of the sub-pixel PX unit region is defined as a fourth sub-pixel electrode unit PX4.

The protrusion units198disposed at the horizontal and vertical intermediate portions196aand196bin each sub-pixel PX unit region may be arranged to be shared with each other.

The protrusion unit198disposed at the edge of the sub-pixel PX unit region may be connected with at least one of the protrusion units198disposed at the horizontal and vertical intermediate portions196aand196b.

Specifically, the first protrusion unit198amay be disposed at the right side of the first sub-pixel electrode unit PX1and the right side of the fourth sub-pixel electrode unit PX4. Here, a region in which the first protrusion unit198ais removed may exist in the right upper corner region of the first sub-pixel electrode unit PX1and the right lower corner region of the fourth sub-pixel electrode unit PX4. The first protrusion unit198amay be connected to the right end of the protrusion unit198disposed at the horizontal intermediate portion196a.

The second protrusion unit198bmay be disposed at the upper side of the first sub-pixel electrode unit PX1and the upper side of the second sub-pixel electrode unit PX2. Here, a region in which the second protrusion unit198bis removed may exist in the right upper corner region of the first sub-pixel electrode unit PX1and the left upper corner region of the second sub-pixel electrode unit PX2. The second protrusion unit198bmay be connected to the upper end of the protrusion unit198disposed at the vertical intermediate portion196b.

The third protrusion unit198cmay be disposed at the left side of the second sub-pixel electrode unit PX2and the left side of the third sub-pixel electrode unit PX3. Here, a region in which the third protrusion unit198cis removed may exist in the left upper corner region of the second sub-pixel electrode unit PX2and the left lower corner region of the third sub-pixel electrode unit PX3. The third protrusion unit198cmay be connected to the left end of the protrusion unit198disposed at the horizontal intermediate portion196a.

The fourth protrusion unit198dmay be disposed at the lower side of the third sub-pixel electrode unit PX3and the lower side of the fourth sub-pixel electrode unit PX4. Here, a region in which the fourth protrusion unit198dis removed may exist in the left lower corner region of the third sub-pixel electrode unit PX3and the right lower corner region of the fourth sub-pixel electrode unit PX4. The fourth protrusion unit198dmay be connected to the lower end of the protrusion unit198disposed at the vertical intermediate portion196b.

The first to fourth protrusion units198ato198dmay be disposed to cover the horizontal stem192aor the horizontal stem192b, which is disposed on each of the sub-pixels.

As such, when the protrusion unit198is removed from the corner region of the sub-pixel PX unit region, the number of the liquid crystal molecules302, which are irregularly arranged in the corner region of the sub-pixel PX unit region by the collision of the liquid crystal molecules302, may be minimized. Therefore, it is possible to prevent the deterioration of the transmittance occurring in the corner region of the sub-pixel PX unit region.

As shown inFIG. 17, the fifth protrusion unit198emay be disposed at each corner region of the sub-pixel PX unit region, and the first to fourth protrusion units198a,198b,198c, and198dmay be disposed in the region adjacent to the end of each of the horizontal and vertical intermediate portions196aand196b. The first to fifth protrusion units198a,198b,198c,198d, and198emay be disposed to be spaced apart from each other.

It may be difficult to arrange the liquid crystal molecules302defined by the average liquid crystal azimuth310at the ends of the horizontal and vertical intermediate portions196aand196b. In the first domain Da, for example, the liquid crystal molecules302are behaved in the direction of the first horizontal electric field F1and the second horizontal electric field F2, and the behaved liquid crystal molecules302secondarily collides with each other, thereby arranging the liquid crystal molecules302at the average liquid crystal azimuth310. However, the force of any one of the first horizontal electric field F1and the second horizontal electric field F2is more greatly applied to the region adjacent to the end of each of the horizontal and vertical intermediate portions196aand196b, and thus it is difficult to arrange the liquid crystal molecules302in the direction of the average liquid crystal azimuth310.

When such forces of electric fields are different from each other, first to fourth protrusion units198a,198b,198c, and198dmay be generated in the region in which the liquid crystal molecules302are irregularly arranged. The region in which the first to fourth protrusion units198a,198b,198c, and198dare not arranged may be a region in which force of an electric field is stably provided.

Therefore, in the region in which the first to fourth protrusion units198a,198b,198c, and198dare not arranged, the liquid crystal molecules302may be stably arranged even when the first to fourth protrusion units198a,198b,198c, and198dare not provided. Further, a fifth protrusion unit198emay be disposed even in the corner region of the pixel PX, in which the liquid crystal molecules302are irregularly arranged by collision.

Further, the first to fourth protrusion units198a,198b,198c, and198dmay be disposed not to cover the horizontal stem192aor the vertical stem192bdisposed in each of the sub-pixel unit.

Therefore, when the first to fourth protrusion units198a,198b,198c, and198dare disposed at the ends of the horizontal and vertical intermediate portions196aand196band the fifth protrusion unit198eis disposed in the corner region of the pixel PX, the number of the liquid crystal molecules302behaving in the direction of the average liquid crystal azimuth310increases, thereby improving the transmittance of the LCD.

As such, when a vector capable of secondarily arranging the liquid crystal molecules302adjacent to the edge of the pixel electrode191is provided, it is possible to prevent the liquid crystal molecules302adjacent to the edge of the pixel electrode191from being inclined in a direction perpendicular to the edge of the pixel electrode191. That is, it is possible to prevent the deterioration of display quality occurring when the liquid crystal molecules302are arranged in a direction parallel to the polarization axis at the edge of the pixel electrode191.

As described above, according to the embodiments of the invention, there is an advantage in that the response speed and transmittance of the LCD may be improved by changing the shape of an electrode and forming the slit pattern and protrusion spacing electrodes in a pixel.

Although certain exemplary embodiments and implementations have been described herein, other exemplary 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.