Patent Publication Number: US-2023143788-A1

Title: Pixel unit and liquid crystal display device

Description:
FIELD OF THE INVENTION 
     The present invention relates to a display technique, and more particularly, to a pixel unit and a liquid crystal display (LCD) device. 
     BACKGROUND OF THE INVENTION 
     Because the pixel size of the 8K LCD device is small, the 4 domain pixel electrode design is adopted in order to raise the aperture ratio of pixels. However, the widths of the strip portions and the widths of the slits are the same in all positions of the 4-domain pixel electrode design such that it has a huge viewing angle deviation. This seriously impacts the display quality of the 8k LCD device and becomes an issue for developing 8k LCD device. 
     Therefore, a new pixel unit and an LCD device need to developed to solve the above-mentioned issue. 
     SUMMARY OF THE INVENTION 
     One objective of an embodiment of the present invention is to provide a pixel unit and a LCD device to solve the issue of the huge viewing angle deviation caused by the same widths of the strip portions and the slits. 
     According to an embodiment of the present invention, a pixel unit is disclosed. The pixel unit comprises four sub-pixel units. Each of the sub-pixel units comprises a pixel electrode, comprising a plurality of strip portions positioned at intervals, wherein two adjacent strip portions define a slit. One strip portion and one slit adjacent to the strip potion are defined as an electrode portion and a width of the electrode portion is a sum of a width of the slit and a width of the strip portion. The width of each of the electrode portions and/or the width of each of the strip portions and/or the width of each of the slits is different. The strip portions and the slits are respectively positioned symmetrically in each of the sub-pixel units. 
     Optionally, the width of each of the electrode portions is different, the width of each of the strip portions is the same, and the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is different, the width of each of the strip portions is different, and the width of each of the slits is same. 
     Optionally, the width of each of the electrode portions is different, the width of each of the strip portions is different, and the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is the same, the width of each of the strip portions is different, and the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is between 5 microns and 6 microns. 
     Optionally, the width of each of the strip portions is between 2 microns and 4 microns. 
     Optionally, the width of each of the slits is between 2 microns and 3 microns. 
     Optionally, the pixel unit further comprises a main electrode, comprising a first main electrode and a second main electrode. The first main electrode is horizontally positioned and the second main electrode is vertically positioned, and the strip portion extends along the second main electrode to an edge of the pixel electrode. An angle between the slit and the first main electrode is one of 35 degree, 40 degree and 45 degree. 
     Optionally, a width evenly changes along a direction from far to near the first main electrode. 
     According to an embodiment of the present invention, a pixel unit is disclosed. The pixel unit comprises four sub-pixel units. Each of the sub-pixel units comprises a pixel electrode, comprising a plurality of strip portions positioned at intervals, wherein two adjacent strip portions define a slit. One strip portion and one slit adjacent to the strip potion are defined as an electrode portion and a width of the electrode portion is a sum of a width of the slit and a width of the strip portion. The width of each of the electrode portions and/or the width of each of the strip portions and/or the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is different, the width of each of the strip portions is the same, and the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is different, the width of each of the strip portions is different, and the width of each of the slits is same. 
     Optionally, the width of each of the electrode portions is different, the width of each of the strip portions is different, and the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is the same, the width of each of the strip portions is different, and the width of each of the slits is different. 
     Optionally, the width of each of the electrode portions is between 5 microns and 6 microns. 
     Optionally, the width of each of the strip portions is between 2 microns and 4 microns. 
     Optionally, the width of each of the slits is between 2 microns and 3 microns. 
     Optionally, the pixel unit further comprises a main electrode, comprising a first main electrode and a second main electrode. The first main electrode is horizontally positioned and the second main electrode is vertically positioned, and the strip portion extends along the second main electrode to an edge of the pixel electrode. An angle between the slit and the first main electrode is one of 35 degree, 40 degree and 45 degree. 
     According to an embodiment of the present invention, an LCD device is disclosed. The LCD device comprises the above-mentioned pixel unit. 
     A pixel unit and an LCD device are disclosed. The pixel unit comprises four sub-pixel units. Each of the sub-pixel unit comprises a pixel electrode. The pixel electrode comprises an electrode portion. The width of the electrode portion is a sum of the width of the strip portion and the width of the slit. The width of each of the electrode portions and/or the width of each of the strip portions and/or the width of each of the slits in different positions is different such that the pixel electrodes in different positions have a different aperture ratio-voltage curve. This improves the viewing angle deviation of the four domain pixel electrode and raises the display quality of the LCD device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To describe the technical solutions in the embodiments of this application more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of this application, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts. 
         FIG.  1    is a diagram of a pixel unit according to an embodiment of the present invention. 
         FIG.  2    is a scale-up diagram of a part of a pixel electrode according to a first embodiment of the present invention. 
         FIG.  3    is a scale-up diagram of a part of a pixel electrode according to a second embodiment of the present invention. 
         FIG.  4    is a scale-up diagram of a part of a pixel electrode according to a third embodiment of the present invention. 
         FIG.  5    is a scale-up diagram of a part of a pixel electrode according to a fourth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     It is understood that terminologies, such as “center,” “longitudinal,” “horizontal,” “length,” “width,” “thickness,” “upper,” “lower,” “before,” “after,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” and “counterclockwise,” are locations and positions regarding the figures. These terms merely facilitate and simplify descriptions of the embodiments instead of indicating or implying the device or components to be arranged on specified locations, to have specific positional structures and operations. These terms shall not be construed in an ideal or excessively formal meaning unless it is clearly defined in the present specification. 
     In addition, the term “first”, “second” are for illustrative purposes only and are not to be construed as indicating or imposing a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature that limited by “first”, “second” may expressly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of “plural” is two or more, unless otherwise specifically defined. 
     All of the terminologies containing one or more technical or scientific terminologies have the same meanings that persons skilled in the art understand ordinarily unless they are not defined otherwise. For example, “arrange,” “couple,” and “connect,” should be understood generally in the embodiments of the present disclosure. For example, “firmly connect,” “detachablely connect,” and “integrally connect” are all possible. It is also possible that “mechanically connect,” “electrically connect,” and “mutually communicate” are used. It is also possible that “directly couple,” “indirectly couple via a medium,” and “two components mutually interact” are used. 
     All of the terminologies containing one or more technical or scientific terminologies have the same meanings that persons skilled in the art understand ordinarily unless they are not defined otherwise. For example, “upper” or “lower” of a first characteristic and a second characteristic may include a direct touch between the first and second characteristics. The first and second characteristics are not directly touched; instead, the first and second characteristics are touched via other characteristics between the first and second characteristics. Besides, the first characteristic arranged on/above/over the second characteristic implies that the first characteristic arranged right above/obliquely above or merely means that the level of the first characteristic is higher than the level of the second characteristic. The first characteristic arranged under/below/beneath the second characteristic implies that the first characteristic arranged right under/obliquely under or merely means that the level of the first characteristic is lower than the level of the second characteristic. 
     Different methods or examples are introduced to elaborate different structures in the embodiments of the present disclosure. To simplify the method, only specific components and devices are elaborated by the present disclosure. These embodiments are truly exemplary instead of limiting the present disclosure. Identical numbers and/or letters for reference are used repeatedly in different examples for simplification and clearance. It does not imply that the relations between the methods and/or arrangement. The methods proposed by the present disclosure provide a variety of examples with a variety of processes and materials. However, persons skilled in the art understand ordinarily that the application of other processes and/or the use of other kinds of materials are possible. 
     As previously mentioned, the conventional pixel unit and LCD device has an issue of huge viewing angle deviation. This issue is because the widths of the strip portions and the widths of the slits are the same in all positions of the 4-domain pixel electrode design. In the following disclosure, an embodiment is disclosed to solve the above-mentioned issue. 
     Please refer to  FIG.  1   .  FIG.  1    is a diagram of a pixel unit according to an embodiment of the present invention. The pixel unit is a fourth domain pixel structure. That is, the pixel unit comprises four sub-pixel units. Each of the sub-pixel units comprises a pixel electrode  1 . The pixel electrode  1  comprises a plurality of strip portions  11  positioned in intervals. In addition, two adjacent strip portions  11  define a slit  12  between the strip portions  11 . The strip potion  11  and its adjacent slit  12  are defined as an electrode portion  10 . The width of the electrode portion  10  is the sum of the width of the strip portion  11  and the width of the slit  12 . That is, the width of the electrode portion  10  is the distance between the centers of two adjacent strip portions  11  or between the centers of two adjacent slits  12 . The width of the electrode portion  10  is the pixel distance of the pixel electrode  1 . 
     The pixel unit comprises a main electrode  2 . The main electrode  2  comprises a first main electrode  21  and a second main electrode  22 , which are positioned across each other. The first main electrode  21  is horizontally positioned and the second electrode  22  is vertically positioned. The strip portion  11  extends from the second main electrode  22  to the edge of the pixel electrode  1  to form a fish bone pattern and to define four domains. 
     The pixel unit further comprises a plurality of scan lines  3  and data lines  4 . The scan lines  3  and the data lines  4  are positioned across each other. The scan lines  3  and the first main electrode  21  are positioned in parallel. The data lines  4  and the second main electrode  22  are positioned in parallel. The scan lines  3  and the data lines  4  surround the sub-pixel unit. The DBS common line  5  is position on the top of the data line  4 . The pixel unit further comprises a switch unit  6 . The switch unit  6  is electrically connected to the pixel electrode  1 , the scan line  3  and the data line  4 . 
     The width of each of the electrode portions  10  and/or the width of each of the strip portions  11  and/or the width of each of the slits  12  is different. This allows the pixel electrode  1  to have different aperture ratio-voltage curves in different positions. This could improve the viewing angle problem. 
     Specifically, through changing the width of the electrode portion  10  (changing the pixel distance of the pixel electrode  1 ), the aperture ratio-voltage curves in different positions become different. Please refer to  FIGS.  2 - 5   , which respectively show a scale-up diagram of the region A in  FIG.  1   .  FIGS.  2 - 5    respectively represent four different embodiments of the pixel electrode  1 . Please note, in the following embodiments utilize adjacent the first electrode portion  101  and the second electrode portion  102  as an example. The first electrode portion  101  comprises the first strip portion  111  and the first slit  121 . The second electrode portion  102  comprises the second strip portion  112  and the second slit  122 . 
     Please refer to  FIG.  2   .  FIG.  2    is a scale-up diagram of a part of a pixel electrode according to a first embodiment of the present invention. In this embodiment, the width of each of the electrode portions  10  is different. The width of each of the strip portions  11  is the same but the width of each of the slits  12  is different. In other words, the widths of the strip portions  11  remain the same. Through changing the widths of the slits  12  in different positions, the electrode portions  10  have different widths in different positions such that the pixel electrode  1  could have different pixel distances in different positions. In this way, the aperture ratio-voltage curves in different positions are different such that the viewing angle could be improved. 
     The widths of the first strip portion  111  and the second strip potion  112  are the same (L). The width of the first slit  121  is S 1 . The width of the second slit  122  is S 2 . Here, S 1  is not equal to S 2 . The width of the first electrode portion  101  is P 1 . The width of the second electrode portion  102  is P 2 . Therefore, P 1  is not equal to P 2 . 
     Please refer to  FIG.  3   .  FIG.  3    is a scale-up diagram of a part of a pixel electrode  1  according to a second embodiment of the present invention. In this embodiment, the width of each of the electrode portions  10  is different. The width of each of the strip portions  11  is different but the width of each of the slits  12  is the same. In other words, the widths of the slits  12  remain the same. Through changing the widths of the strip portions  11  in different positions, the electrode portions  10  have different widths in different positions such that the pixel electrode  1  could have different pixel distances in different positions. In this way, the aperture ratio-voltage curves in different positions are different such that the viewing angle could be improved. 
     The width of the first slit  121  and the second slit  122  are the same (S). The width of the first strip portion  111  is L 1  and the width of the second strip potion  112  is L 2 . Here, L 1  is not equal to L 2 . The width of the first electrode portion  101  is P 1 . The width of the second electrode portion  102  is P 2 . Therefore, P 1  is not equal to P 2 . 
     From  FIG.  2    and  FIG.  3   , the widths of the electrode portions  10  evenly changes along the direction far to near the first main electrode  21 . In another embodiment, the width variation of the electrode portions  10  could be not limited to a fixed value. 
     Please refer to  FIG.  4   .  FIG.  4    is a scale-up diagram of a part of a pixel electrode according to a third embodiment of the present invention. In this embodiment, the width of each of the electrode portions  10  is different. The width of each of the strip portions  11  is different and the width of each of the slits  12  is also different. Through changing the widths of the strip portions  11  and the slits  12  in different positions, the electrode portions  10  have different widths in different positions such that the pixel electrode  1  could have different pixel distances in different positions. In this way, the aperture ratio-voltage curves of the pixel electrode  1  in different positions are different such that the viewing angle could be improved. 
     The width of the first strip portion  111  is L 1  and the width of the second strip potion  112  is L 2 . Here, L 1  is not equal to L 2 . The width of the first slit  121  is S 1  and the width of the second slit  122  is S 2 . S 1  is not equal to S 2 . The width of the first electrode portion  101  is P 1 . The width of the second electrode portion  102  is P 2 . P 1  is not equal to P 2 . 
     Please refer to  FIG.  5   .  FIG.  5    is a scale-up diagram of a part of a pixel electrode according to a fourth embodiment of the present invention. In this embodiment, the width of each of the electrode portions  10  is the same. The width of each of the strip portions  11  is different and the width of each of the slits  12  is also different. In other words, the widths of the electrode portions  10  could remain the same. Through changing the widths of the strip portions  11  and the slits  12  in different positions, the aperture ratio-voltage curves of the pixel electrode  1  in different positions are different such that the viewing angle could be improved. 
     The width of the first strip portion  111  is L 1  and the width of the second strip potion  112  is L 2 . Here, L 1  is not equal to L 2 . The width of the first slit  121  is S 1  and the width of the second slit  122  is S 2 . S 1  is not equal to S 2 . The width of the first electrode portion  101  and the width of the second electrode portion  102  are the same (P). 
     The width of each of the electrode portions  10  is between 5 microns and 6 microns. 
     The width of each of the strip portions  11  is between 2 microns and 4 microns. 
     The width of each of the slits  12  is between 2 microns and 3 microns. 
     The angle between the slit  12  and the first main electrode  21  is one of 35 degree, 40 degree and 45 degree. This is not a limitation of the present invention. 
     In order to clearly illustrate the above-mentioned embodiments of the present invention, only one of the four domains is used for illustration. Please note, the four different sub-pixel units in the pixel unit all obey the spirit of the present invention. Furthermore, the strip portions  11  and the slits  12  are symmetrically positioned in each of the sub-pixel units to increase the symmetry of the pixel electrode  1 . 
     In addition, an LCD device is disclosed. The LCD device comprises the above-mentioned pixel unit. The LCD device could be an LCD display or a mobile device, a wearable device, or a VR device having an LCD display. This is not a limitation of the present invention. 
     A pixel unit and an LCD device are disclosed. The pixel unit comprises four sub-pixel units. Each of the sub-pixel unit comprises a pixel electrode. The pixel electrode comprises an electrode portion. The width of the electrode portion is a sum of the width of the strip portion and the width of the slit. The width of each of the electrode portions and/or the width of each of the strip portions and/or the width of each of the slits in different positions is different such that the pixel electrodes in different positions have a different aperture ratio-voltage curve. This improves the viewing angle deviation of the four domain pixel electrode and raises the display quality of the LCD device. 
     Above are embodiments of the present invention, which does not limit the scope of the present invention. Any modifications, equivalent replacements or improvements within the spirit and principles of the embodiment described above should be covered by the protected scope of the invention.