Liquid crystal display device and method of fabricating the same

A liquid crystal display device includes first and second substrates, gate and data lines formed on the first substrate and crossing each other to define a pixel region, a first common electrode in a first part of the pixel region, the first common electrode having a plate shape, a plurality of first pixel electrodes directly over the first common electrode and at a first fixed interval in the first part of the pixel region, a second pixel electrode alternately arranged with a second common electrode at a second fixed interval in a second part of the pixel region, and a layer of liquid crystal molecules between the first and second substrates.

This application claims the benefit of Korean Patent Application No. 10-2006-132299 filed on Dec. 22, 2006 and Korean Patent Application No. 10-2007-037007 filed on Apr. 16, 2007, which are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relates to a liquid crystal display (LCD) device, and more particularly, to an LCD device and a method of fabricating the same. Although embodiments of the invention are suitable for a wide scope of applications, it is particularly suitable for obtaining a rapid response speed and a high aperture ratio.

2. Discussion of the Related Art

In general, active matrix (AM) LCD devices have high speed and are widely used for flat type televisions, mobile computers and monitors. Among the AM LCD devices, a twisted nematic (TN) mode LCD device is typically used, in which two electrodes are respectively formed on two substrates. When a voltage is applied across the two electrodes, directors of the liquid crystal are realigned with a twist of 90°. The TN mode LCD device has attracted attention due to its advantageous display properties, such as great contrast and high resolution. However, the TN mode LCD device also has the problem of a narrow viewing angle.

To overcome this problem of TN mode LCD device having a relatively narrow viewing angle, other devices have been proposed for use, such as in-plane switching (IPS) mode LCD device and fringe field switching (FFS) mode LCD device. In the IPS mode LCD device, two electrodes are formed on one substrate such that the directors of the liquid crystal are twisted between surfaces of alignment layers. In the FFS mode LCD device, common and pixel electrodes are formed of transparent conductors and a small interval is maintained between the common and pixel electrodes such that liquid crystal molecules are driven by a fringe field generated between the common and pixel electrodes.

Both the IPS and FFS modes have a similar operation method in that each of the IPS and FFS modes includes the electrodes formed on one substrate that receive the applied operating voltages. However, the arrangement of electrodes of the IPS mode is different from that of the FFS mode. Hereinafter, a related art LCD device will be described with reference to the accompanying drawings.

FIG. 1is a plan view of illustrating the related art FFS mode LCD device. Referring toFIG. 1, the related art FFS mode LCD device includes gate lines3and data lines7of opaque metal crossing each other to define a pixel region (P), a common line10aparallel to the gate line3, a thin film transistor (TFT) adjacent to the crossing of the gate lines3and data lines7, a counter electrode2having a plate shape formed and made of a transparent conductor in the pixel region (P), and a pixel electrode9aoverlapping the counter electrode2and having the shape of comb including a plurality of teeth.

The thin film transistor (TFT) includes a semiconductor layer (not shown) formed over a predetermined portion of the gate line3, a source electrode7aprotruding from the data line7, and a drain electrode7bformed at a predetermined interval from the source electrode7a. The source and drain electrodes7aand7bare positioned at both sides of the semiconductor layer. The pixel electrode9ais formed as one body with an extension part9bso that the pixel electrode9ais electrically connected with the drain electrode7bsuch that the respective end portions corresponding to the comb teeth of pixel electrode9aare connected with one another by the extension part9b. Thus, the drain electrode7bis electrically connected with the extension part9bby the contact part.

The common line10aincludes common electrodes10b, which are positioned adjacent to the data lines7at the both sides of pixel region P. The common line10aand common electrode10bis electrically connected with the counter electrode2. At this time, the common electrode10bis offset from the pixel electrode9aand a portion of counter electrode2.

In the FFS mode having the above-mentioned electrode structure, the counter electrode2is formed throughout the pixel region (P), and the counter electrode2is formed in a different layer from the pixel electrode9a. Thus, the fringe field is formed between the pixel electrode9aand the counter electrode2, wherein the fringe field is formed with the electric field being curved toward the counter electrode2from the center of pixel electrode9a. The electric field may be also formed in the overlap portion between the counter electrode2and the pixel electrode9a. As the LCD device is turned-on, the liquid crystal is largely moved based on the electric field. A large operating voltage is required because the liquid crystal molecules need to be greatly moved. Unless the operating voltage is sufficiently large to control the liquid crystal, the response speed is relatively lower so that an afterimage phenomenon occurs.

As shown in the drawings, the plurality of pixel electrodes9may be connected with one another by the extension part9bformed at one end of pixel electrode9. In addition, another extension part having a bar shape may be formed at the other end of pixel electrode9. That is, the pixel electrode9may be a plate provided with a plurality of slits. To solve the afterimage problem, the IPS mode LCD device is more widely used.

FIG. 2is a plan view of illustrating the related art IPS mode LCD device. Referring toFIG. 2, the related art IPS mode LCD device includes gate lines21and data lines20crossing each other to define a pixel region (P), a thin film transistor (TFT) which is formed adjacent to the crossing of the gate lines21and data lines20to switch on/off a voltage, pixel electrodes28aand common electrode29aalternate with each other in the pixel region (P), a common line22is formed parallel to the gate line21, an extension part28electrically connects the a drain electrode of thin film transistor with the pixel electrodes28aas one body, and a common electrode connection part29connects the common electrodes29aas one body. The thin film transistor (TFT) includes a gate electrode23which protrudes from the gate line21, a semiconductor layer (not shown) over the gate electrode23, a source electrode25protruding from the data line20, and a drain electrode27positioned at a predetermined interval from the source electrode25. The source and drain electrodes25and27are positioned at both sides of the semiconductor layer.

In the related art IPS mode LCD device of the above-mentioned structure, the IPS mode electric field occurs between the pixel electrodes28aand the common electrodes29athat alternate with each other at intervals, whereby the liquid crystal molecules are driven by the IPS mode electric field. In this case, the liquid crystal molecules are not smoothly driven just above the pixel electrodes28aand the common electrodes29asince the electric field is not formed above the pixel electrodes28aand the common electrodes29a.

Accordingly, the related art LCD device has the following disadvantages. While applying the voltage across the common and pixel electrodes in the related art IPS mode LCD device, the in-plane electric field is not formed just above the common and pixel electrodes. Thus, the liquid crystal molecules are not properly driven just above the common and pixel electrodes such that the aperture ratio and light transmittance are lowered. In the related art FFS mode LCD device where the counter electrode of plate shape is formed throughout the area of pixel region, and slitted or fingered pixel electrode is formed thereon, a large operating voltage is required to move the liquid crystal molecules. Unless the operating voltage is sufficiently large to control the liquid crystal, the response speed of liquid crystal is low and it is difficult to obtain the rapid response speed for displaying moving images. As a result of not obtaining a rapid response speed, an afterimage can occur on the display panel.

SUMMARY OF THE INVENTION

Accordingly, embodiments of the present invention are directed to an LCD device and a method of manufacturing the same that substantially obviates one or more problems due to limitations and disadvantages of the related art.

Another object of the present invention is to provide an LCD device and a method of manufacturing the same to obtain a high aperture ratio.

An object of the present invention is to provide an LCD device and a method of manufacturing the same to obtain rapid response.

An object of the present invention is to provide an LCD device and a method of manufacturing the same to obtain a wide viewing angle.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a liquid crystal display device includes first and second substrates facing each other, gate and data lines formed on the substrate and crossing each other to define a pixel region, a first common electrode in a first part of the pixel region, the first common electrode having a plate shape, a plurality of first pixel electrodes directly over the first common electrode and at a first fixed interval in the first part of the pixel region, a second pixel electrode alternately arranged with a second common electrode at a second fixed interval in a second part of the pixel region, and a layer of liquid crystal molecules between the first and second substrates.

In another embodiment, a liquid crystal display device includes first and second substrates facing each other, gate and data lines formed on the substrate and crossing each other to define a pixel region, a first common electrode in a center part of the pixel region, the first common electrode having a plate shape, a plurality of first pixel electrodes formed directly over the first common electrode and provided at a first fixed interval in the center part of the pixel region, second pixel electrodes alternately arranged with second common electrodes at a second fixed interval in upper and lower parts of the pixel region, and a layer of liquid crystal molecules between the first and second substrates.

In another embodiment, a liquid crystal display device includes first and second substrates facing each other, gate and data lines formed on the first substrate and crossing each other to define a pixel region, first common electrodes in upper and lower parts of the pixel region, the first common electrodes each having a plate shape, a plurality of first pixel electrodes formed directly over each of the first common electrodes and provided at a first fixed interval in the upper and lower parts of the pixel region, second pixel electrodes alternately arranged with second common electrodes at a second fixed interval in a center part of the pixel region, and a layer of liquid crystal molecules between the first and second substrates.

In a further embodiment, a method of fabricating a liquid crystal display device includes preparing first and second substrates, forming gate and data lines formed on the first substrate that cross each other to define a pixel region, forming a first common electrode in a first part of the pixel region, the first common electrode having a plate shape, forming a plurality of first pixel electrodes directly over the first common electrode and at a first fixed interval in the first part of the pixel region, forming a second pixel electrode alternately arranged with a second common electrode at a second fixed interval in a second part of the pixel region, and forming a layer of liquid crystal molecules between the first and second substrates.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Hereinafter, an LCD device according to the present invention and a method of manufacturing the same will be explained with reference to the accompanying drawings.

FIG. 3is a plan view of illustrating an electrode shape of one pixel of an LCD device according to a first embodiment of the present invention.FIG. 4is a cross-sectional view along line I-I′ ofFIG. 3. As shown inFIGS. 3 and 4, the LCD device according to the first embodiment of the present invention includes a substrate100, another opposing substrate (not shown), a gate line (not shown,131ofFIG. 9) and a data line (not shown,132ofFIG. 9) crossing each other on the substrate100to define a pixel region P1including lower, central and upper parts, a thin film transistor formed adjacent to a crossing point of the gate line131and data lines132, first common electrodes101having a plate shape formed in the lower and upper parts of the pixel region P1, first pixel electrodes103aformed at intervals directly over the first common electrodes101, second pixel and common electrodes103band111alternately formed in the central part of the pixel region P1, a first connector (not shown) electrically connecting the first pixel electrode103awith the second pixel electrode103b, a second connector (not shown) to electrically connecting the first common electrode101with the second common electrode111, and a layer of liquid crystal molecules (not shown) formed between the two opposing substrates.

The first pixel electrode103a, the second pixel electrode103b, the first common electrode101and the second common electrode111may be formed of transparent materials, such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO). As the liquid crystal molecules are driven above and between the electrodes by the above-mentioned transparent electrodes, the light passes through the transparent electrodes so as to prevent the aperture ratio or transmittance from being lowered. The first pixel electrode103aand the second pixel electrode103bmay be formed in the same layer, as shown inFIG. 4. In the alternative, the first pixel electrode103aand the second pixel electrode103bmay be formed in different layers by patterning the second pixel electrode103btogether with the first common electrode101.

As shown inFIG. 4, the first common electrode101and the second common electrode111may be formed in the different layers. In the alternative, the first common electrode101and the second common electrode111may be formed in the same layer. In either case, the first pixel electrodes103a, the second pixel electrodes103b, the first common electrode101and second common electrodes111are formed of the transparent electrodes while the first common electrode101and the first pixel electrodes103aare formed in different layers. This is because the first common electrode101is formed as a plate shape in the lower and upper parts of the pixel region P1. That is, there is not enough space in the layer of first common electrode101to form the first pixel electrodes103a.

The first pixel electrodes103a, the second pixel electrode103band the second common electrode111are formed as bent-shaped structures. More specifically, the first pixel electrodes103ain the upper part of pixel region P1are formed as (rightward and leftward) symmetric bent-shapes pointing in a first direction while the first pixel electrodes103ain lower part of the pixel region P1are also formed as (rightward and leftward) symmetric bent-shapes pointing in a second direction opposite to the first direction. Further, the second pixel electrodes103bin the central part of the pixel region P1are formed as (rightward and leftward, upward and downward) symmetric bent-shapes pointing in both the first and second directions with respect to the center point ‘O’ of pixel region. The second pixel electrodes103bin the central part of the pixel region P1are parallel with the second common electrodes111formed in the central part of the pixel region P1. Also, the second common electrodes111are parallel with an adjacent the first pixel electrode103a. There is also a third common electrode121formed with two opposite isosceles triangles symmetric with the center point of pixel region P1in the horizontal direction, as shown inFIG. 3. Alternatively, the third common electrode121may be taken out.

Although not shown, the third common electrode121includes a third connector (not shown) which is electrically connected with the first common electrode101and the second common electrode111. The same voltage is applied to the first common electrodes101, second common electrodes111and third common electrode121to drive the liquid crystal molecules in the pixel region P1. The electric field in the lower and upper parts of the pixel region P1with the first common electrode101having the plate shape is different from the electric field in the central part of pixel region P1where the second common electrodes111are fingers.

In the lower and upper parts of the pixel region P1where the first common electrode101is a plate shape, a fringe electric field is formed from the first pixel electrode103ain accordance with bent-shape toward the first common electrode101. Above the first pixel electrodes103a, liquid crystal molecules are reoriented so as improve the aperture ratio and light transmittance. The first common electrodes101are respectively formed in the lower and upper parts of pixel region P1and not in the central part of the pixel region P1. Also, the first pixel electrodes103aare symmetrically formed in the lower and upper parts with respect to the central part of the pixel region P1with their bent-shapes pointing in opposite direction so as to obtain increased viewing angles in the lower and upper directions, thereby widening the viewing angle.

In the central part of pixel region P1where the first common electrode101is not a plate shape, the second pixel electrodes103balternates with the second common electrode111and have the same shape as the second common electrodes111. Also, the second pixel electrodes103bare symmetrically positioned with respect to the third common electrode121, and the second common electrodes111are symmetrically positioned with respect to the third common electrode121. Also, the second pixel electrode103band the second common electrode111are provided at intervals such that the IPS mode electric field occurs between the second pixel electrode103band the second common electrode111rapidly aligns liquid crystal molecules in parallel to the IPS mode electric field. Accordingly, the light transmittance and aperture ratio of the pixel region P1are improved by combining the two types of electric fields to obtaining a wide viewing angle and rapid response speed.

Due to the fact that the first pixel electrodes103a, second pixel electrodes103band the second common electrodes111are symmetric bent-shape with respect to the center point O of the pixel region, four domains corresponding to 1, 2, 3 and 4 parts are formed when operating voltages are applied to the electrodes (the first and second pixel electrodes, and the first and second common electrodes). So it is possible to gain a wide viewing angle.

In the LCD device according to the first embodiment of the present invention, the central part of the pixel region P1has rapid response speed while the lower and upper parts of the pixel region P1increase of aperture ratio and light transmittance since the edges of lower and upper parts of the pixel region P1have good aperture ratio and light transmittance and the lower and upper parts of the pixel region P1are symmetric with respect to the center point O of the pixel region P1. Further, each pixel region P1has a wide viewing angle. In the electrode structure according to the first embodiment of the present invention, the transmittance is increased as compared with that of the related art IPS mode LCD device. In the aspect of response speed, if the first pixel electrodes103aare positioned with small intervals on the first common electrode101and the interval between the first pixel electrodes103a is smaller than the interval between the second common electrode111and the second pixel electrode103b, the intensity of fringe field is increased between the first common electrode101and the first pixel electrode103a. Accordingly, when applying the operating voltage, the liquid crystal molecules in the lower and upper parts of the pixel region P1are moved quickly while liquid crystal molecules in the central part of the pixel region P1are operated by the IPS mode electric field generated among the second pixel electrode103b, the second common electrode111and the third common electrode121. Thus, it is possible to improve the response speed even though the same voltage level is applied to the LCD device according to the present invention as compared with the related art IPS mode LCD device. If the interval between adjacent first pixel electrodes103ain the lower and upper parts of the pixel region P1is smaller than the interval between adjacent second pixel electrode103band second common electrode111, and is also smaller than the interval between adjacent second pixel electrode103band third common electrode121, the intensity of fringe field is increased over the first common electrode101, and the transmittance is increased about 19.44% as compared with that of the related art IPS mode LCD device (FIG. 9).

FIG. 5is a plan view of illustrating an electrode shape of one pixel of an LCD device according to the second embodiment of the present invention.FIG. 6is a cross-sectional view along line II-II′ ofFIG. 5. Referring toFIGS. 5 and 6, the LCD device according to the second embodiment of the present invention includes a substrate100, another opposing substrate (not shown), a gate line (not shown,131ofFIG. 7) and a data line (not shown,132ofFIG. 7) crossing each other on the substrate100to define a pixel region P2, including lower, central and upper parts, a thin film transistor (not shown) formed adjacent to the crossing of the gate lines131and data lines132, a first common electrode201in the central part of the pixel region P2and having a plate shape, first pixel electrodes203aformed directly over the first common electrode201at intervals, second pixel and common electrodes203band211alternately formed in the lower and upper parts of the pixel region P2, a first connector (not shown) electrically connecting the first pixel electrode203awith the second pixel electrode203b, a second connector (not shown) to electrically connecting the first common electrode201with the second common electrode211, and a layer of liquid crystal molecules (not shown) formed between the two opposing substrates.

The first pixel electrodes203a, the second pixel electrodes203b, the first common electrode201and the second common electrodes211can be formed of transparent material, such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO). When the liquid crystal molecules are driven by the above-mentioned transparent electrodes, the light passes through the transparent electrodes so as prevent the aperture ratio and light transmittance from being lowered. The first pixel electrode203aand the second pixel electrode203bmay be formed in the same layer, as shown inFIG. 6. In the alternative, the first pixel electrodes203aand the second pixel electrodes203may be formed in the different layers by patterning the second pixel electrode203btogether with the first common electrode201.

As shown inFIG. 6, the first common electrode201and the second common electrodes211can be formed in different layers. In the alternative, the first common electrode201and the second common electrodes211may be formed in the same layer. In either case, the first pixel electrode203a, second pixel electrodes203b, the first common electrode201and second common electrodes211are formed of the transparent material while the first common electrode201and the first pixel electrodes203aare formed in different layers. This is because the first common electrode201in the central part of the pixel region P2has a plate shape. That is, there is not enough space in the layer of first common electrode201to form the first pixel electrodes203a.

The first pixel electrodes203a, the second pixel electrodes203band the second common electrodes211are formed as bent-shaped structures. More specifically, the second pixel electrode203bin the upper part of the pixel region P2are formed as symmetric bent-shapes pointing in a first direction while the second pixel electrode203bin lower part of the pixel region P2are also formed as symmetric bent-shapes pointing in a second direction opposite to the first direction. Further, the first pixel electrodes203ain the central part of the pixel region P2are formed as symmetric bent-shapes pointing in both the first and second directions. The second pixel electrodes203bin the upper and lower parts of the pixel region P2are parallel with the second common electrodes211formed in the central part of the pixel region P2. There is also a third pixel electrode213formed with two opposite isosceles triangles symmetric at the center point of pixel region P2in the horizontal direction, as shown inFIG. 5. Also, the first pixel electrodes203aare symmetrically positioned with respect to the third pixel electrode213formed along the central line of horizontal direction of the pixel region P2. The second pixel electrodes203band the second common electrodes211formed in the lower part of the pixel region P2are symmetric with those formed in the upper part of the pixel region P2.

The interval between adjacent first pixel electrode203aand third pixel electrode213is smaller than the interval between adjacent second pixel electrode203band second common electrode211. Thus, the intensity of fringe field is increased over the first common electrode201such that the liquid crystal molecules are reoriented smoothly.

Although not shown, the third common electrode213includes a third connector (not shown) electrically connected to the first pixel electrode203aand the second pixel electrode203b. The same voltage is applied to the first pixel electrodes203a, the second pixel electrodes203band the third pixel electrode213to drive the liquid crystal molecules in the pixel region P2.

In the LCD device according to the second embodiment of the present invention, the fringe field is formed in the central part of the pixel region P2, and the IPS mode field is formed in the lower and upper parts of the pixel region P2. The light transmittance and aperture ratio of pixel region P2are improved by combining the two types of electric fields, while also obtaining a wide viewing angle and rapid response speed. In the electrode structure according to the second embodiment of the present invention, the transmittance is increased as compared with that of the related art IPS mode LCD device. Accordingly, when applying an operating voltage, the liquid crystal molecules in the central part of the pixel region P2are moved quickly while liquid crystal molecules in the upper and lower parts of pixel region are operated by the IPS mode electric field generated among the second pixel electrode203b, the second common electrode. In comparison with the related art IPS mode LCD device, the LCD device according to the present invention has rapid response speed.

Due to the fact that the first pixel electrodes203a, second pixel electrodes203band the second common electrodes211are symmetric bent-shape with respect to the center point O of the pixel region, four domains corresponding to 1, 2, 3 and 4 parts are formed when operating voltages are applied to the electrodes (the first and second pixel electrodes, and the first and second common electrodes). So it is possible to obtain a wide the viewing angle.

FIG. 7is a plan view of illustrating an electrode shape of one pixel of an LCD device according to the third embodiment of the present invention.FIG. 8is a cross-sectional view along line III-III′ ofFIG. 7. Referring toFIGS. 7 and 8, the LCD device according to the third embodiment of the present invention includes a substrate200, another opposing substrate (not shown), a gate line (not shown,131ofFIG. 9) and a data line (not shown,132ofFIG. 9) crossing each other on the substrate200to define a pixel region P3including lower, central and upper parts, a thin film transistor (not shown) formed adjacent to a crossing of the gate lines131and data lines132, a first common electrode221in the central part of the pixel region P3having a plate shape, first pixel electrodes233aformed directly over the first common electrode221at intervals, second pixel electrodes233band second common electrodes231alternately formed in the lower and upper parts of the pixel region P3, a first connector (not shown) electrically connecting the first pixel electrode233awith the second pixel electrode233b, a second connector (not shown) electrically connecting the first common electrode221with the second common electrode231, and a layer of liquid crystal molecules (not shown) formed between the two opposing substrates.

The interval between adjacent two first pixel electrodes233a, or a first pixel electrode233aand third pixel electrode233cis smaller than the interval between an adjacent second pixel electrode233band second common electrode231. Thus, the intensity of fringe field is increased over the first common electrode221such that the liquid crystal molecules are smoothly reoriented by the fringe field. In the electrode structure according to the third embodiment of the present invention, the transmittance is increased by about 29.84% as compared with that of the related art IPS mode LCD device. In the aspect of response speed, if the first pixel electrodes233aare positioned with small intervals on the first common electrode221, the intensity of fringe field is increased among the first common electrode221, the first pixel electrode233aand the third pixel electrode233c.

When applying the operating voltage, the liquid crystal molecules are operated by a FFS mode electric field in the central part of pixel region while the lower and upper parts of pixel region are operated by a IPS mode electric field between the second pixel electrode233band the second common electrode231. In comparison with the related art IPS mode LCD device, the LCD device according to embodiments of the present invention has rapid response speed. Through control of the interval spacing between adjacent two first pixel electrodes as well as the width of the first pixel electrodes, it is observed that the transmittance is increased about 15˜32% as compared with that of the related art IPS mode LCD device.

FIG. 9is a plan view of illustrating an LCD device according to the fourth embodiment of the present invention.FIG. 10is a cross-sectional view along line IV-IV′ ofFIG. 9. Referring toFIGS. 9 and 10, the LCD device according to the fourth embodiment of the present invention includes connectors which electrically connect the first and second pixel electrodes with each other, and other connectors which electrically connect the first to third common electrodes with one another. Also, the interval between adjacent two first pixel electrodes103ain the lower and upper parts of the pixel region P4is smaller than the interval between an adjacent second pixel electrode103band second common electrode111, and is also smaller than the interval between an adjacent second pixel electrode103band third common electrode121. Thus, the intensity of fringe field is increased over the first common electrode101such that the liquid crystal molecules are smoothly operated by the fringe field. As shown inFIGS. 9 and 10, the first and second pixel electrodes are formed as one body, and the first to third common electrodes are formed as one body. Also, the first and second pixel electrodes are formed in different layers than the first to third common electrodes.

Referring toFIGS. 9 and 10, the LCD device according to the third embodiment of the present invention includes a gate line131, a data line132, the common electrode141, and the pixel electrode151. The common electrode141has a plate shape formed in lower and upper parts of the pixel region P4with slits in the center part of the pixel region to provide finger-shaped common electrodes141at an interval. Above the common electrode141, a plurality of pixel electrodes151are formed at an interval. In the central part of pixel region, the finger-shaped pixel electrode151and common electrode141alternate with each other. The pixel electrodes151formed on the common electrode141, and the pixel and common electrodes151and141formed in the central part of pixel region have a bent-shaped structure.

When dividing the pixel region into the lower and upper parts by the central line of horizontal direction, the electrodes of upper part are formed in ashape, and the electrode of lower part are formed in invertedshape. That is, the electrodes in the upper part are symmetric in shape with the electrodes of lower part. Along the central line of horizontal direction, there is a common electrode141which is formed with two opposite isosceles triangles being symmetric with the center point of pixel region, wherein the two isosceles triangles may be connected with each other, or may be apart from each other. In this case, the isosceles triangle may be any size based on the bent structure of pixel electrodes151provided in the lower and upper parts of pixel region.

The pixel electrodes151and common electrodes141are formed of transparent material, such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO), to thereby prevent the aperture ratio and light transmittance from being lowered. The pixel electrodes151are formed as one body such that the pixel electrodes151are electrically connected with one another. Also, the common electrodes141are formed as one body, whereby the common electrodes141are electrically connected with one another.

Then, a thin film transistor is formed adjacent to a crossing point of the gate line131and the data line132. The thin film transistor includes a gate electrode131a that protrudes from the gate line131, a gate insulation layer137that is formed on the substrate100including the gate electrode131, a semiconductor layer134which is formed on the gate insulation layer137above the gate electrode131a,and source and drain electrodes132aand132bwhich are formed at both sides of the semiconductor layer134. In addition, the semiconductor layer134is formed of an amorphous silicon layer and an impurity layer provided below the source and drain electrodes132aand132b.

The gate line131including the gate electrode131ais formed of the different material from the common electrode141. For example, the gate electrode131aand the gate line131are patterned with the light-shielding metal material, and the common electrode141is patterned with transparent material.

A passivation layer138is formed on and between the source and drain electrodes132aand132b. The pixel electrode has a contact part150provided in a contact hole of the passivation layer to connect to the drain electrode132bof pixel region. Thus, an electric signal can be applied to the pixel electrode through the drain electrode132b.

FIGS. 11A-11Care simulation views when operating voltages are applied to the electrodes in an IPS mode or the related art, the fourth embodiment and the third embodiment of the present invention, respectively.

ReferringFIGS. 11A and 11B, it is found that the fourth embodiment of the present invention has a higher transmittance of about 19.44% (0.094457/0/0790829-1) than the IPS mode when operating voltages are applied to the electrodes. Also, referringFIGS. 11A and 11B, it is also found that the third embodiment of the present invention has a higher transmittance of about 29.84% (0.094457/0/0790829-1) than the IPS mode.

In the same method of the LCD device according to the first embodiment of the present invention, the LCD device according to the fourth embodiment of the present invention is operated by applying an operating voltage to drive the liquid crystal molecules. As mentioned above, the pixel region may be divided into the plurality of parts as well as the three parts described above. If the pixel region is divided into the plurality of parts, the first common electrode of plate shape is formed in parts of the pixel region alternating with parts of the pixel region having finger common electrodes. To make the viewing angle symmetric in the lower and upper directions when having the pixel region in the data line direction, the electrodes of the upper part (pixel and common electrodes) are symmetric with the electrodes of lower part.

As mentioned above, the LCD device according to embodiments of the present invention and the method of manufacturing the same has advantages. For example, because each pixel region is divided into a plurality of parts to include a FFS mode and IPS mode structures at the same time. When applying the operating voltage, the liquid crystal molecules are driven between first pixel electrodes and also above the first pixel electrodes formed over the first common electrode of plate shape such that the aperture ratio is improved. If the interval between the adjacent two of first pixel electrodes formed on the first common electrode of plate shape is smaller than the interval between the adjacent two of second pixel and common electrodes, the intensity of the fringe field is increased between the first pixel electrode and the first common electrode. Accordingly, as the intensity of electric field between the first pixel electrodes formed is increased over the first common electrode, the liquid crystal molecules are driven quickly above the first common electrode. So that the liquid crystal molecules corresponding to the region between the second pixel electrodes and the second common electrodes, adjacent to the first common electrode, are influenced by moving of the liquid crystal molecules above the first common electrode and more quickly driven so as to obtain rapid response. Also, electrodes in pixel region are symmetric bent-shape with respect to the center point of the pixel region, in such that four domains are formed with respect to the center point O of the pixel region when operating voltages are applied to the electrodes, so that the viewing angle is improved by the lower and upper parts and the right and left parts. As a result, the LCD device according to the present invention has high aperture ratio, good light transmittance, rapid response speed and wide viewing angle.