Abstract:
A pixel structure including a substrate, a scan line, a first data line and a first pixel unit is provided. The scan line and the first data line are disposed on the substrate. The first pixel unit includes a first active device and a first pixel electrode. The first active device is electrically connected to the scan line and the first data line. The first pixel electrode electrically connected to the first active device has a first stripe pattern and a plurality of first branches. One side of the first stripe pattern is connected to the first branches extended toward the scan line, and the other side of the first stripe pattern is overlapped with the scan line. The overlapped width of the first stripe pattern with the scan line is substantially equal to 40% to 90% of the width of the first stripe pattern.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority benefit of Taiwan application serial no 98142528, filed on Dec. 11, 2009. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to pixel structure, and more particularly, to a pixel structure capable of improving the display quality. 
         [0004]    2. Description of Related Art 
         [0005]    Nowadays, the market demands the liquid crystal display (LCD) panel to develop its functions towards high contrast ratio, no gray scale inversion, little color shift, high luminance, full color, high color saturation, high response speed and wide viewing angle. Currently, the technologies capable of fulfilling the demands include the twist nematic (TN) LCD having a wide viewing film, the in-plane switching (IPS) LCD, the fringe field switching (FFS) LCD and the multi-domain vertically aligned (MVA) LCD. 
         [0006]    In a conventional MVA-LCD panel, an alignment structure is formed, such that liquid crystal (LC) molecules in different areas tilt in different angles and accomplish the wide viewing angle effect. The alignment structure includes alignment protrusions and alignment slits disposed on electrodes. However, the alignment protrusion and the liquid crystal molecules surrounding the alignment slit usually have disclination and thereby causing light leakage or disclination phenomenon, and further lowering the display contrast of the LCD panel. Thus, a light shielding layer corresponding to the alignment protrusions or the alignment slits is disposed to improve the leakage of light or disclination phenomenon. However, an aperture ratio of the display is limited thereby. 
         [0007]    Hence, how to balance between the capacitance of the demanding of the wide viewing angle of the pixel structure and the opening ratio of the pixel structure has become a challenge in the design of the pixel structure. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a pixel structure having a high aperture ratio. 
         [0009]    The invention provides a pixel structure capable of reducing the discontinuously display phenomenon to obtain better displaying quality. 
         [0010]    The present invention provides a pixel structure comprising a substrate, a scan line, a first data line and a first pixel unit. The scan line and the first, data line are disposed on the substrate. The first pixel unit includes an active device and a first pixel electrode. The active device is electrically connected to the scan line and the first data line. The first pixel electrode is electrically connected to the first active device and the first pixel electrode has a first stripe pattern substantially parallel to the scan line and a plurality of first branches electrically connected to the first stripe pattern. One side of the first stripe pattern is connected to the first branches extending towards to the scan line and the other side of the first stripe pattern overlaps the scan line. A first overlapping width of the first stripe pattern with the scan line is about 40%˜90% of a width of the first stripe pattern. 
         [0011]    According to one embodiment of the present invention, the first branches are separated from a projection of the first data line projecting onto the substrate, and the first pixel electrode is apart from the first data line with a distance. 
         [0012]    According to one embodiment of the present invention, the first pixel electrode further comprises a main trunk portion and a branch portion, and the main trunk portion is parallel to the first data line, and the branch portion is parallel to the scan line. The first pixel unit is divided into four domains through the main trunk portion and the branch portion, and the first branches outwardly extend from an intersection of the main trunk portion and the branch portion. The first branches in each of the domains are substantially parallel to one another. 
         [0013]    According to one embodiment of the present invention, the first pixel unit further comprises a storage capacitor structure. The capacitor structure comprises a bottom capacitor electrode and an upper capacitor electrode. The upper capacitor electrode is located over the bottom capacitor electrode and the upper capacitor electrode is in the same layer as the first pixel electrode. The main trunk portion and the upper capacitor electrode are separated from each other, and the upper capacitor electrode is connected to the first pixel electrode through one of the branches near the first data line. 
         [0014]    According to one embodiment of the present invention, the pixel structure further comprises a color filter disposed between the first active device and the first pixel electrode. The color filter has an opening substantially located at the intersection of the main trunk portion and the branch portion of the first pixel electrode, and the first pixel electrode is electrically connected to the first active device through the opening. Further, the first pixel unit comprises a contact pattern located at the intersection of the main trunk portion and the branch portion of the first pixel electrode and connected to a drain of the first active device. The first pixel electrode is connected to the contact pattern through the opening, and the first pixel electrode covers the contact pattern in a full range manner. Alternatively, a portion of the branches overlap at least a portion of the contact pattern. 
         [0015]    According to one embodiment of the present invention, the pixel structure further comprises a second pixel unit and a second data line. The second pixel unit comprises a second active device and a second pixel electrode. The second active device is electrically connected to the scan line and the second data line. The second pixel electrode is electrically connected to the second active device, and the second pixel electrode has a plurality of second branches, and the second branches extend towards to the first data line and the second data line and cross over the first data line and the second data line. 
         [0016]    According to one embodiment of the present invention, the first pixel unit and the second pixel unit are configured between the first data line and the second data line. 
         [0017]    According to one embodiment of the present invention, the second pixel electrode further comprises a second stripe pattern substantially parallel to the scan line. One side of the second stripe pattern is connected to the second branches extending towards to the scan line, and the other side of the second stripe pattern overlaps the scan line. More particularly, a second overlapping width of the second stripe pattern with the scan line is about 40%˜90% of a width of the second stripe pattern of the second pixel electrode. 
         [0018]    According to one embodiment of the present invention, a projection of the first branches are separated from a projection of the adjacent first data line projecting onto the substrate, and the first pixel electrode is apart from the adjacent first data line with a distance. Specifically, the distance is about 3˜9 micrometers. 
         [0019]    The present invention provides a pixel structure comprising a substrate, a scan line, a first data line, a second data line, a first pixel unit and a second pixel unit. The scan line, the first data line and the second data line are disposed on the substrate. The first pixel unit is located between the first data line and the second data line, and the first pixel unit includes a first active device and a first pixel electrode. The active device is electrically connected to the scan line and the first data line. The first pixel electrode is electrically connected to the first active device, and the first pixel electrode comprises a plurality of first branches. The first branches outwardly extend from a center of the first pixel unit, and a projection of the first branches are separated from a projection of the adjacent first data line projecting onto the substrate, and the first pixel electrode is apart from the adjacent first data line with a distance. The second pixel unit is located between the first data line and the second data line, and the second pixel unit includes a second active device and a second pixel electrode. The second active device is electrically connected to the scan line and the second data line. The second pixel electrode is electrically connected to the second active device, and the second pixel electrode has a plurality of second branches. The second branches extend towards to the first data line and the second data line and cross over the first data line and the second data line. 
         [0020]    According to one embodiment of the present invention, the pixel structure further comprises a color filter located between the first active device and the first pixel electrode and between the second active device and the second pixel electrode. 
         [0021]    The present invention provides a pixel structure comprising a substrate, a scan line, a first data line, a first pixel unit and a color filter. The scan line and the first data line are disposed on the substrate. The first pixel unit is located between the first data line and the second data line, and the first pixel unit includes a first active device and a first pixel electrode. The active device is electrically connected to the scan line and the first data line. The first pixel electrode is electrically connected to the first active device, and the first pixel electrode comprises a plurality of first branches, a main trunk portion and a branch portion. The main trunk portion is parallel to the first data line, and the first branches outwardly extend from an intersection of the main trunk portion and the branch portion. The color filter is disposed between the first active device and the first pixel electrode and the color filter has an opening substantially located at the intersection of the main trunk portion and the branch portion. The first pixel electrode is electrically connected to the first active device through the opening. 
         [0022]    According to one embodiment of the present invention, the first pixel unit comprises a contact pattern located at the intersection of the main trunk portion and the branch portion and connected to a drain of the first active device. The first pixel electrode is connected to the contact pattern through the opening, and the first pixel electrode covers the contact pattern in a full range manner. 
         [0023]    According to one embodiment of the present invention, the first pixel unit comprises a contact pattern located at the intersection of the main trunk portion and the branch portion of the first pixel electrode and connected to a drain of the first active device. The first pixel electrode is connected to the contact pattern through the opening, and a portion of the branches overlap at least a portion of the contact pattern. 
         [0024]    The present invention provides a pixel structure comprising a substrate, a scan line, a first data line and a first pixel unit. The scan line and the first data line are disposed on the substrate. The first pixel unit is located between the first data line and the second data line, and the first pixel unit comprises a first active device, a first pixel electrode and a storage capacitor structure. The first active device is electrically connected to the scan line and the first data line. The first pixel electrode is electrically connected to the first active device, and the first pixel electrode comprises a plurality of first branches, a main trunk portion and a branch portion. The main trunk portion is parallel to the first data line, and the first pixel unit is divided into four domains through the main trunk portion and the branch portion. The first branches outwardly extend from an intersection of the main trunk portion and the branch portion, and the first branches in each of the domains are substantially parallel to one another. The capacitor structure comprises a bottom capacitor electrode and an upper capacitor electrode. The upper capacitor electrode is located over the bottom capacitor electrode and the upper capacitor electrode is in the same layer as the first pixel electrode. The main trunk portion and the upper capacitor electrode are separated from each other, and the upper capacitor electrode is connected to the first pixel electrode through one of the branches near the first data line. 
         [0025]    Accordingly, by properly controlling the ratio of the overlapping width of the stripe pattern of the pixel electrode in the pixel structure with the scan line to the width of the stripe pattern, the light leakage while the pixel structure displays an image can be decreased and the aperture ratio can be increased. In one embodiment, by controlling the design of the pixel electrode around the opening of the color filter, the disclination phenomenon due to unclear tilt directions of the liquid crystal molecules while the pixel structure is used to display an image can be suppressed. In one embodiment, since the upper capacitor electrode is connected to the pixel electrode through the branches near the periphery of the data line, a better display quality can be obtained. Moreover, in another embodiment, the branches of the pixel electrode of the second pixel unit of the pixel structure extending towards to the adjacent data line and crossing over the data lines would also lead to a better display quality. Hence, according to the aforementioned strategies, the disclination phenomenon happening in each domains of the pixel structure while the pixel structure of the present invention displays an image can be respectively eliminated. Thus, the light leakage can be decreased, the aperture ratio can be improved and the disclination can be suppressed. Therefore, the display quality is well improved. 
         [0026]    In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanying figures are described in detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
           [0028]      FIG. 1  is a schematic view of a pixel structure according to the first embodiment of the present invention. 
           [0029]      FIG. 2A  is a partial enlarged view of the region A of the pixel structure in  FIG. 1 . 
           [0030]      FIG. 2B  is a schematic cross-sectional view of  FIG. 2A . 
           [0031]      FIG. 3  is a schematic partial enlarged view of a pixel structure according to the second embodiment of the present invention. 
           [0032]      FIG. 4A  is a top view of a pixel structure according to the third embodiment of the present invention. 
           [0033]      FIG. 4B  is a partial enlarged view of the pixel structure in  FIG. 4A . 
           [0034]      FIG. 5A  is a schematic partial enlarged view showing a first pixel electrode in the pixel structure in  FIG. 4A  electrically connected to a first active device through an opening of a color filter. 
           [0035]      FIG. 5B  is a schematic partial enlarged view showing another embodiment of the first pixel electrode in the pixel structure in  FIG. 4A  electrically connected to the first active device through the opening of a color filter. 
           [0036]      FIG. 6  is a top view and a schematic partial enlarged view of a pixel structure according to the fourth embodiment of the present invention. 
           [0037]      FIG. 7A  and  FIG. 7B  are schematic cross-sectional views of the pixel structure in  FIG. 6  respectively along line AA and line BB. 
           [0038]      FIG. 8A  and  FIG. 8B  are a schematic partial enlarged view and a schematic cross-sectional view of the pixel structure in  FIG. 6  respectively. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0039]    The present invention provides a pixel structure. The elements at the location of the pixel structure where the disclination phenomenon happens due to unclear tilt directions of the liquid crystal molecules while the pixel structure is used to display an image are individually improved. For instance, the design of the pixel electrode, the arrangement relationship between the pixel electrode and the scan line, the arrangement relationship between the pixel electrodes of the main pixel unit and the sub-pixel unit and the data lines of the main pixel unit and the sub-pixel unit or the design of the pixel electrode around the opening of the color filter can be adjusted. According to the relative relationship between the elements of the pixel structure and the design of the stacked area, the disclination phenomenon likely happening on the displayed image can be eliminated. Thus, the light leakage is decreased, the aperture ratio is increased and the display quality is improved. Several embodiments of the present invention will be described in details in the following with reference to accompany the drawings. 
       First Embodiment 
       [0040]      FIG. 1  is a schematic view of a pixel structure according to the first embodiment of the present invention. As shown in  FIG. 1 , a pixel structure  200  is configured on a substrate  202  to define a plurality of pixel regions P on the substrate  202 . In order to more clarify the related elements in the pixel structure  200 ,  FIG. 1  only shows the pixel structure  200  in one of the pixel regions P as an exemplar of the present invention. 
         [0041]    As shown in  FIG. 1 , the pixel structure  200  comprises a scan line  210 , a first data line  220  and a first pixel unit  230 A which are configured on the substrate  202 . In the present embodiment, the first pixel unit  230 A comprises a first active device  232 A and a first pixel electrode  234 A. The first active device  232 A is electrically connected to the scan line  210  and the first data line  220 . The first pixel electrode  234 A is electrically connected to the first active device  232 A and the first pixel electrode  234 A has a first stripe pattern  240 A substantially parallel to the scan line  210  and a plurality of first branches  242 A electrically connected to the first stripe pattern  240 A. One side of the first stripe pattern  240 A is connected to the first branches  242 A extending towards to the scan line  210  and the other side  240 AS 2  of the first stripe pattern  240 A overlaps a portion of the scan line  210 . More particularly, the overlapping width of the first stripe pattern  240 A with the scan line  210  is about 40%˜90% of the width of the first stripe pattern  240 A. Accordingly, the display quality of the pixel structure  200  can be optimized. 
         [0042]    More specifically,  FIG. 2A  is a partial enlarged view of the region A of the pixel structure in  FIG. 1  and  FIG. 2B  is a schematic cross-sectional view of  FIG. 2A . As shown in  FIG. 2A  and  FIG. 2B , a slit  280  is located between the adjacent first branches  242 A of the first pixel electrode  234 A. As shown in  FIG. 2A  and  FIG. 2B , it is assumed that the overlapping width of the first stripe pattern  240 A with the scan line  210  is denoted as W 1  and the width of the first stripe pattern  240 A without overlapping with the scan line  210  is denoted as W 2 , wherein the width W of the stripe width  240  is the sum of W 1  and W 2 . In the present embodiment, the overlapping width W 1  of the first stripe pattern  240 A with the scan line  210  is about 40%˜90% of the width W of the first stripe pattern  240 A. Further, the overlapping width W 1  of the first stripe pattern  240 A with the scan line  210  is about 1.5˜3.5 micronmeters. When the pixel structure  200  is applied to the design of the ultra high aperture, the preferred ratio of W 1  to W 2  is 4:1. That is, the ratio of W 1  to W is about 80%, which can adequately decrease the light leakage phenomenon. Moreover, when the pixel structure  200  is applied to the designs of the color filter on array (COA) or the black matrix on array (BOA), the preferred ratio of W 1  to W 2  is about 1:1. That is, the ratio of W 1  to W is about 50%, which can adequately decrease the light leakage phenomenon so as to obtain a better display quality. 
         [0043]    Taking the COA as an exemplar,  FIG. 2B  is a schematic cross-sectional view of the pixel structure in  FIG. 2A  line BB. As shown in  FIG. 2A  and  FIG. 2B , the pixel structure  200  further comprises a color filter  250 . The color filter  250  is located between the first pixel electrode  234 A and the scan line  210 . The overlapping width W 1  of the first stripe pattern  240 A with the scan line  210  and the width W 2  of the first stripe pattern  240 A without overlapping with the scan line  210  are 2.5 micronmeters. Furthermore, it should be noticed that, as shown in  FIG. 1 , in the present embodiment, the projection of the first branches  242 A projecting on the substrate  202  are separated from the projection of the first data line  220  projecting on the substrate  202 . Also, the first pixel electrode  234 A is apart from the first data line  220  with a distance S and the distance S is at least about 3 micronmeters. Preferably, the distance S is about 3˜9 micronmeters. 
         [0044]    Hence, as for the pixel structure  200  of the first embodiment of the present invention, by properly controlling the ratio of the overlapping width W 1  of the first stripe pattern  240 A with the scan line  210  to the width of the first stripe pattern  240 A, the light leakage is decreased, the aperture ratio is increased and the display quality is improved. 
         [0045]    Moreover, the designer can integrate the pixel structure of the first embodiment with portions or all of the techniques mentioned in the following embodiments according to the practical requirement of the product so as to further improve the display effect of the pixel structure. Also, the designer can only implement one of the techniques mentioned in the following embodiments to instantly improve the disclination phenomenon and to improve the display quality. 
       Second Embodiment 
       [0046]      FIG. 3  is a schematic partial enlarged view of a pixel structure according to the second embodiment of the present invention. As shown in  FIG. 3 , in a pixel structure  300  of the present embodiment, the first pixel unit  330 A is similar to the first pixel unit  230 A of the first embodiment. The difference between the first pixel unit  330 A and the first pixel unit  230 A is that the first pixel unit  330 A further comprises a storage capacitor structure  260 . 
         [0047]    More specifically, as shown in  FIG. 3 , the first pixel electrode  234 A has a main trunk portion  310  parallel to the first data line  220  and a branch portion  320  parallel to the scan line  210 . The first pixel unit  330 A is divided into four domains R 1 , R 2 , R 3  and R 4  through the main trunk portion  310  and the branch portion  320 . The first branches  242 A outwardly extend from the intersection of the main trunk portion  310  and the branch portion  320 . The first branches  242 A in each of the domains R 1 , R 2 , R 3  and R 4  are substantially parallel to one another. When the pixel structure  300  is used to display an image, the liquid crystal molecules located over the first pixel unit  330 A can tilt towards to four different directions in different tilt levels so as to achieve the display effect of the wide viewing angle. However, the present invention is not limited to the number of the domains of each of the pixel unit. That is, the types and the numbers of the main trunk portion  310  and the branch portion  320  can be designed according to the requirement of the product. 
         [0048]    It should be noticed that the pixel structure  300  of the present embodiment can further comprises a storage capacitor structure  260 . The storage capacitor structure  260  includes a bottom capacitor electrode  260 B and an upper capacitor electrode  260 U. As shown in the top view of the pixel structure, the first pixel electrode  234 A is located between the bottom capacitor electrode  260 B and the scan line  210 . Moreover, as shown in  FIG. 3 , in the cross-sectional view of the pixel structure, the upper capacitor electrode  260 U is located above the bottom capacitor electrode  260 B. The upper capacitor electrode  260 U can be the same layer as the first pixel electrode  234 A. That is, the upper capacitor electrode  260 U and the first pixel electrode  234 A can be formed from the same film layer, and made of the same material and can be formed in the same photolithography process. It should be noticed that the disclination phenomenon easily happens at the portion of the displayed image corresponding to the connection portion of the main trunk portion  310  and the upper electrode  260 U. Hence, in the present embodiment as shown in  FIG. 3 , the main trunk portion  310  is separated from the upper capacitor electrode  260 U (the portion B shown in  FIG. 3 ) and the upper capacitor electrode  260 U is connected to the first pixel electrode  234 A through the first branches  242 A near the periphery of the data line (the portion C shown in  FIG. 3 ). In other words, the connection portion of the upper capacitor electrode  260 U and the first pixel electrode  234 A is located at the corner portion of the first pixel electrode  234 A. Thus, while the pixel structure  300  is used to display an image, a better display effect can be obtained. 
         [0049]    Noticeably, in the present embodiment, the pixel structure  300  mainly adopts the adequate connection relationship between the pixel electrode in the pixel unit and the upper capacitor electrode  260 U of the storage capacitor structure  260  to decrease the light leakage, to increase the aperture ratio and to improve the display quality. Although the pixel structure  300  of the present embodiment is described in a way of integrating the techniques of the first embodiment and the second embodiment, the designer can solely utilize that the upper capacitor electrode  260 U is connected to the pixel electrode through the first branches  242 A near the periphery of the data line to decrease the disclination phenomenon and to improve the display effect according to the practical requirements. The present invention, according to the practical requirements of the product, is not limited to that the pixel structure should be accompanied with the first stripe pattern mentioned in the first embodiment. 
       Third Embodiment 
       [0050]      FIG. 4A  is a top view of a pixel structure according to the third embodiment of the present invention and  FIG. 4B  is a partial enlarged view of the pixel structure in  FIG. 4A . As shown in  FIG. 4A  and  FIG. 4B , a pixel structure  400  of the present embodiment is similar to the pixel structures mentioned in the previous embodiments except that a first pixel unit  430 A of the pixel structure  400  of the present embodiment further comprises a color filter  250  located between the first active device  232 A and the first pixel electrode  234 A. For more clarifying, the color filter  250  is removed from the left of  FIG. 4A  and is individually shown at the right of  FIG. 4A . 
         [0051]    As shown in  FIG. 4A  and  FIG. 4B , in the present embodiment, the pixel structure  400  is a pixel structure with the COA. As shown in  FIG. 4A  and  FIG. 4B , the color filter  250  has an opening H. The opening H is substantially located at the intersection X of the main trunk portion  310  and the branch portion  320 , and the first pixel electrode  234 A is electrically connected to the first active device  232 A through the opening H. More specifically, the first pixel electrode  234 A is electrically connected to a contact pattern  410  at the intersection X of the main trunk portion  310  and the branch portion  320  through the opening H. 
         [0052]    For more clarifying, the partial enlarged view of the intersection X of the main trunk  310  and the branch portion  320  is used to describe the present embodiment. 
         [0053]      FIG. 5A  is a schematic partial enlarged view showing a first pixel electrode in the pixel structure in  FIG. 4A  electrically connected to a first active device through an opening of a color filter. As shown in  FIG. 5A  and  FIG. 4A , the first pixel unit  430 A further comprises a contact pattern  410  at the intersection X of the main trunk portion  310  and the branch portion  320 . The contact pattern  410  is connected to a drain  232 D (as shown in  FIG. 4A ) of the first active device  232 A. In more detail, the contact pattern  410  can, for example, extend towards to the location below the opening H of the color filter  250  from the drain  232 D of the active device  232 A. The first pixel electrode  234 A is connected to the contact pattern  410  through the opening H. More particularly, the first pixel electrode  234 A covers the contact pattern  410  in a full range form. In further detail, the so-called full range form is that the projection of the first pixel electrode  234 A projecting onto the substrate  202  covers the contact pattern  410 . As shown in  FIG. 5A , the first pixel electrode  234 A as a whole covers the contact pattern  410 . As shown in the top view of the pixel structure  400 , the contact pattern  410  is located within the coverage of the first pixel electrode  234 A and the periphery of the contact pattern  410  is apart from the first pixel electrode  234 A with a distance D. The distance D is about 1˜6 micronmeters. 
         [0054]    Further, the layout that the first pixel electrode is electrically connected to the first active device through the opening of the color filter, except for the layout shown in  FIG. 5A , also can be the layout shown in  FIG. 5B .  FIG. 5B  is a schematic partial enlarged view showing another embodiment of the first pixel electrode in the pixel structure in  FIG. 4A  electrically connected to the first active device through the opening of a color filter. As shown in  FIG. 5B , more, particularly, a portion of the first branches  242 A of the first pixel electrode  234 A overlap at least a portion of the contact pattern  410 . In more detail, as shown in  FIG. 5B , a portion of the first branches  242 A extend towards to the location over the contact pattern  410  so that the slit  430  between the first branches  242 A is directly located above the contact pattern  410 . It should be noticed that the first branches  242 A of the first pixel electrode  234 A covers the region around the opening H of the color filter  250  as shown in  FIG. 5A  or  FIG. 5B  so that the disclination phenomenon easily happening at the connection portion of the opening H of the color filter  250  and the first pixel electrode  234 A can be eliminated and the viewer cannot perceives the disclination effect. Thus, the pixel structure  400  can provide a relatively better display quality. 
         [0055]    Although the pixel structure  400  of the present embodiment is described in a way of integrating the techniques of the previous embodiments, the designer can solely utilize the design of the present embodiment in which the pixel electrode is controlled to be arranged around the opening of the color filter to decrease the disclination phenomenon and to improve the display effect according to the practical requirements. The present invention, according to the practical requirements of the product, is not limited to that the pixel structure mentioned above. 
       Fourth Embodiment 
       [0056]      FIG. 6  is a top view and a schematic partial enlarged view of a pixel structure according to the fourth embodiment of the present invention. As shown in  FIG. 6 , in the present embodiment, the pixel structure  500  comprises a scan line  210 , a first data line  220 , a second data line  520 , a first pixel unit  530 A and a second pixel unit  530 B. As shown in  FIG. 6 , the first pixel unit  530 A and the second pixel unit  530 B are located between the first data line  220  and the second data line  520 . More specifically, in the pixel structure  500 , the second active device  532 B and the first active device  232 A are electrically connected to the same scan line  210 , and the second active device  532 B and the first active device  232 A are electrically connected to the different data lines respectively. 
         [0057]    As shown in  FIG. 6 , the second pixel unit  530 B comprises the second active device  532 B and the second pixel electrode  534 B. The second active device  532 B is electrically connected, to the scan line  210  and the second data line  520 , and the second pixel electrode  534 B is electrically connected to the second active device  532 B. More particularly, as shown in the enlarged view, the second pixel electrode  534 B has a plurality of second branches  242 B and the second branches  242 B extend towards to the first data line  220  and the second data line  520  and cross over the first data line  220  and the second data line  520 . 
         [0058]    Furthermore,  FIG. 7A  and  FIG. 7B  are schematic cross-sectional views of the pixel structure in  FIG. 6  respectively along line AA and line BB. As shown in  FIG. 7A , in the first pixel unit  530 A of the present embodiment, the projection of the first branches  242 A of the first pixel unit  234 A projecting on the substrate  202  are separated from the projection of the first data line  220  projecting on the substrate  202 . Also, the first pixel electrode  234 A is apart from the first data line  220  with a distance S and the distance S is at least about 3 micronmeters. Preferably, the distance S is about 3˜9 micronmeters. Then, as shown in  FIG. 7B , in the second pixel unit  530 B, the second pixel electrode  534 B has a plurality of second branches  242 B, and the second branches  242 B extend towards to the first data line  220  and the second data line  520  and further cross over the first data line  220  and the second data line  520 . That is, the second branches  242 B of the second pixel electrode  534 B extend from one side of the second data line  520  towards to the opposite side of the second data line  520 . In one embodiment, the protruding length L of the second branches  242 B of the second pixel electrode  534 B protruding from the second data line  520  is, for example, about 2 micronmeters. 
         [0059]    Noticeably, when the pixel structure  500  of the present embodiment is used to display an image, the first pixel unit  530 A is used as a primary displaying unit and the second pixel unit  530 B is used as a secondary displaying unit. Hence, the disclination phenomenon happening at the region, of the second pixel electrode  534 B adjacent to the data line can be alleviated and even completely eliminated. Thus, viewer hardly perceives the disclination effect on the displayed image. Further, the second pixel unit  530 B used as the secondary displaying unit usually has a feature of lower gray scale. Thus, even the second branches  242 B of the second pixel electrode  534 B cross over the second data line  520 , there is no concern about the signal interference. In other words, the pixel structure  500  can provides a relatively better display quality. 
         [0060]    Although the pixel structure  500  of the present embodiment is described in a way of integrating the techniques of the previous embodiments, the designer can solely utilize the design of the present embodiment in which the second branches of the second pixel electrode of the second pixel unit extend towards to the adjacent data line and cross over the data line to decrease the disclination phenomenon and to improve the display effect according to the practical requirements. The present invention, according to the practical requirements of the product, is not limited to that the pixel structure mentioned above. 
         [0061]    Moreover, the arrangement of the second pixel electrode  534 B of the present embodiment can adopt the arrangement of the first pixel  234  of the first embodiment to further eliminate the disclination phenomenon while the pixel structure displays an image. In detail,  FIG. 8A  is a schematic partial enlarged view of the pixel structure in  FIG. 6  and  FIG. 8B  is a schematic cross-sectional view of the pixel structure in  FIG. 6 . As shown in  FIG. 8A  and  FIG. 8B , a slit  430  is located between the second branches  242 B of the second pixel electrode  534 B. As shown in  FIG. 8A  and  FIG. 8B , the second pixel electrode  534 B also comprises a second stripe pattern  240 B substantially parallel to the scan line  210  (as shown in  FIG. 6 ). In the present embodiment, one side of the second stripe pattern  240 B of the second pixel electrode  534 B is connected to the second branches  242 B of the second pixel electrode  534 B extending towards to the scan line  210 , and the other side of the second stripe pattern  240 B of the second pixel electrode  534 B overlaps a portion of the scan line  210 . More specifically, an overlapping width of the second stripe pattern  240 B of the second pixel electrode  534 B with the scan line  210  is about 40%˜90% of a width of the second stripe pattern  240 B of the second pixel electrode  534 B. Further, the overlapping width of the second stripe pattern  240 B with the scan line  210  is about 1.5˜15 micronmeters. In other words, it is assumed that the overlapping width of the second stripe pattern  240 B with the scan line  210  is denoted as W 1  and the width of the second stripe pattern  240 B without overlapping with the scan line  210  is denoted as W 2 , wherein the width. W of the stripe width  240  is the sum of W 1  and W 2 . When the pixel structure  500  is applied to the design of the ultra high aperture, the preferred ratio of W 1  to W 2  is 4:1. Hence, the light leakage phenomenon can be adequately decreased. Moreover, when the pixel structure  500  is applied to the designs of the color filter on array (COA) or the black matrix on array (BOA), the preferred ratio of W 1  to W 2  is about 1:1. Thus, the light leakage phenomenon can be adequately decreased to obtain a better display quality. In one embodiment, the overlapping width W 1  of the second stripe pattern  240 B with the scan line  210  and the width W 2  of the second stripe pattern  240 B without overlapping with the scan line  210  are 2.5 micronmeters. 
         [0062]    In summary, the pixel structure of the present invention have at least the following advantages. 
         [0063]    In the present invention, by properly controlling the ratio of the overlapping width of the stripe pattern of the pixel electrode in the pixel structure with the scan line to the width of the stripe pattern, the light leakage while the pixel structure displays an image can be decreased and the aperture ratio can be increased. 
         [0064]    Also, in the present invention, by controlling the design of the pixel electrode around the opening of the color filter, the disclination phenomenon due to unclear tilt directions of the liquid crystal molecules while the pixel structure is used to display an image can be suppressed. 
         [0065]    Moreover, in the present invention, the upper capacitor electrode is connected to the first pixel electrode through the branches near the periphery of the data line so that the disclination phenomenon due to unclear tilt direction of the liquid crystal molecules can be suppressed while the pixel structure displays an image and a relatively better display quality can be obtained. 
         [0066]    Further, in the present invention, the second branches of the second pixel electrode of the second pixel unit extend towards to the adjacent data line and cross over the data line so that the disclination phenomenon due to unclear tilt directions of the liquid crystal molecules while the pixel structure is used to display an image can be suppressed and a relatively better display quality can be obtained. 
         [0067]    Although the invention has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims not by the above detailed descriptions.