Patent Publication Number: US-9905177-B2

Title: Pixel structure, array substrate, display panel and display device

Description:
TECHNICAL FIELD 
     Embodiments of the present disclosure relate to a pixel structure, an array substrate, a display panel and a display apparatus. 
     BACKGROUND 
     Thin film transistor liquid crystal displays (TFT-LCD) have characteristics of thin thickness, low power consumption, no radiation and the like. The TFT-LCDs have been developed in a fast pace and occupied a leading position of a current panel display market. Now, the TFT-LCDs have been applied widely in various products having a large, middle or small size which cover almost main electronic products of a nowadays information society. Application of the TFT-LCDs in products having large sizes includes application in liquid crystal televisions and high definition digital televisions. 
     SUMMARY 
     A least one embodiment of the disclosure provides a pixel structure, an array substrate, a display panel and a display device, to resolve a problem that a pixel aperture ratio of a sub pixel unit is decreased, which is caused by increasing of an area of a TFT in the sub pixel unit for improving the driving ability of the TFT. 
     A least one embodiment of the disclosure provides a pixel structure, which includes: a first pixel electrode and a second pixel electrode which are arranged along a first direction, and a thin film transistor which is provided between the first pixel electrode and the second pixel electrode; the first pixel electrode comprises a first extension electrode extending toward the second pixel electrode, and the second pixel electrode comprises a second extension electrode extending toward the first pixel electrode; the thin film transistor comprises a gate electrode, a source electrode, a first drain electrode and a second drain electrode which are insulated from each other; the source electrode comprises a first opening and a second opening, the first drain electrode is electrically connected with the first extension electrode and extends into the first opening, and the second drain electrode is electrically connected with the second extension electrode and extends into the second opening. 
     A least one embodiment of the disclosure provides an array substrate comprising a sub pixel unit array formed on a substrate. Each sub pixel unit comprises the pixel structure provided by the above mentioned embodiment. 
     A least one embodiment of the disclosure provides a display panel, comprising the array substrate provided by the above mentioned embodiment. 
     A least one embodiment of the disclosure provides a display device, comprising the display panel provided by the above mentioned embodiment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to clearly illustrate the technical solution of the embodiments of the disclosure, the drawings of the embodiments will be briefly described in the following; it is obvious that the described drawings are only related to some embodiments of the disclosure and thus are not limitative of the disclosure. 
         FIG. 1  is a schematic diagram of a first type of a pixel structure according to an embodiment of the disclosure; 
         FIG. 2  is an enlarged schematic diagram of a source electrode, a first drain electrode and a second drain electrode shown in  FIG. 1 ; 
         FIG. 3  is a schematic diagram of a second type of a pixel structure according to an embodiment of the disclosure; 
         FIG. 4  is an enlarged schematic diagram of a source electrode, a first drain electrode and a second drain electrode shown in  FIG. 3 ; 
         FIG. 5  is a schematic diagram of a third type of a pixel structure according to an embodiment of the disclosure; 
         FIG. 6  is a partial schematic diagram of a first type of an array substrate according to an embodiment of the disclosure; and 
         FIG. 7  is a partial schematic diagram of a second type of an array substrate according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In order to make objects, technical details and advantages of the embodiments of the disclosure apparent, the technical solutions of the embodiments will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. Apparently, the described embodiments are just a part but not all of the embodiments of the disclosure. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the disclosure. 
     During research, it is noted by the inventors of the application that, for a liquid crystal television, a TFT on an array substrate having stronger driving ability is needed, because each sub pixel unit in the liquid crystal television has a relatively large area. Currently, an area of the TFT is often increased for improving the driving ability of the TFT, but the TFT having a larger area occupies a display region of the sub pixel unit, which causes a pixel aperture ratio of the sub pixel unit to be decreased. 
     Referring to  FIG. 1  to  FIG. 4 , a pixel structure  100  provided by an embodiment of the application includes a first pixel electrode  1  and a second pixel electrode  2  which are arranged along a first direction (for example, a longitudinal direction shown in  FIGS. 1 and 3 ), and a thin film transistor (referred to as TFT) which is provided between the first pixel electrode  1  and the second pixel electrode  2 . The first pixel electrode  1  includes a first extension electrode  11  extending toward the second pixel electrode  2 , and the second pixel electrode  2  includes a second extension electrode  21  extending toward the first pixel electrode  1 . The TFT  3  includes a gate electrode  34 , a source electrode  31 , a first drain electrode  32  and a second drain electrode  33  which are insulated from each other. As shown in  FIG. 2  and  FIG. 4 , the source electrode  31  includes a first opening  311  and a second opening  312 . The first drain electrode  32  is electrically connected with the first extension electrode  11  and extends into the first opening  311 , and the second drain electrode  33  is electrically connected with the second extension electrode  21  and extends into the second opening  312 . 
     In the TFT  3 , the gate electrode  34  can be provided above or below the source electrode  31 . In addition, the TFT  3  can further include an active layer (not shown in figures) provided between the gate electrode  34  and the source electrode  31 . 
     For example, the first direction can be a column direction or a row direction of a sub pixel unit array, or an inclined direction (for example, a diagonal direction along the first pixel electrode or the second pixel electrode). 
     In the embodiments of the disclosure, the source electrode  31  includes a first opening  311  and a second opening  312 . A width to length ratio of a channel region formed by the first drain electrode  32  and the second drain electrode  33  is increased, so that the driving ability of the TFT  3  can be improved. The first pixel electrode  1  and the second pixel electrode  2  have extension electrodes which extend toward each other, respectively. The first drain electrode  32  and the second drain electrode  33  are electrically connected to the corresponding extension electrodes, respectively. Thus, a region between the first pixel electrode  1  and the second pixel electrode  2  is used effectively, so that the display region of the sub pixel unit will not be occupied by the first drain electrode  32  and the second drain electrode  33 , thereby achieving that a pixel aperture ratio of the sub pixel unit is improved while the driving ability of the TFT is improved. 
     Various kinds of specific pixel structures  100  can be obtained according to different kinds of shapes and different positions of the source electrode  31 , the first drain electrode  32  and the second drain electrode  33 . Examples are illustrated as follows. 
     For example, with respect to the pixel structure  100  shown in  FIG. 1 , an enlarged schematic view of the source electrode  31 , the first drain electrode  32  and the second drain electrode  33  of the pixel structure  100  is shown in  FIG. 2 . In  FIG. 2 , the source electrode  31  is in an S shape. Orientations of the first opening  311  and the second opening  312  are opposite to each other. The first drain electrode  32  and the second drain electrode  33  are located at different sides of the source electrode  31 . Of course, the first extension electrode  11  of the first pixel electrode  1  and the second extension electrode  21  of the second pixel electrode  2  can be modified, and in combination with the pixel structure  100  in  FIG. 1 , the pixel structure  100  shown in  FIG. 5  can be obtained (similar numerical references have similar meanings in  FIGS. 1 and 5 ). 
     For example, with respect to the pixel structure  100  shown in  FIG. 3 , an enlarged schematic view of the source electrode  31 , the first drain electrode  32  and the second drain electrode  33  of the pixel structure  100  is shown in  FIG. 4 . In  FIG. 4 , the source electrode  31  is in an M shape ( FIG. 4  shows the M-shaped source electrode  31  after being rotated counterclockwise by 90°). Orientations of the first opening  311  and the second opening  312  are the same. The first drain electrode  32  and the second drain electrode  33  are located at a same side of the source electrode  31 . 
     Opening directions of the first opening  311  and the second opening  312  can be selected flexibly, so that conditions of orientations, shapes and the like of the first drain electrode  32  and the second drain electrode  33  are accommodated. For example, opening directions of the first opening  311  and the second opening  312  are perpendicular to the first direction, in order to simplify designs. 
     In at least one embodiment of the disclosure, vertical projections of the first extension electrode  11 , the second extension electrode  21  and the gate electrode  34  (for example, orthogonal projections projected along a direction perpendicular to a surface at which the first pixel electrode or the second pixel electrode is located) have no overlapped regions. In this way, parasitic capacitance may not be produced between the gate electrode  34  and the first extension electrode  11  as well as the second extension electrode  21 , when the pixel structure provided by embodiments of the disclosure is applied on an array substrate. 
     For example, the first drain electrode  32  and the first extension electrode  11  can be electrically connected by a via hole, and the second drain electrode  33  and the second extension electrode  21  can be electrically connected by another via hole 
     Beneficial effects of the embodiment of the disclosure include the following: the first pixel electrode and the second pixel electrode have extension electrodes which extend to each other respectively, the first drain electrode and the second drain electrode are electrically connected with the corresponding extension electrodes respectively, and the first drain electrode and the second drain electrode can extend into corresponding openings along a horizontal direction from respective connections between respective drain electrodes and respective extension electrodes, which causes the TFT to have a larger area, i.e., the driving ability of the TFT is improved; the region between the first pixel electrode and the second pixel electrode can be effectively used by the above mentioned designs, so that the display region of the sub pixel unit will not be occupied by the first drain electrode and the second drain electrode, thereby improving a pixel aperture ratio of the sub pixel unit while the driving ability of the TFT is improved. 
     Referring to  FIG. 6  and  FIG. 7 , at least one embodiment of the disclosure provides an array substrate  200 , which includes a sub pixel unit array formed on a substrate  201 . The sub pixel unit  210  has the pixel structure  100  provided by any of the above mentioned embodiments. 
     For example, a gate line  202  having a zigzag line shape is provided between the first pixel electrode  1  and the second pixel electrode  2  of each sub pixel unit which belongs to a same row. The gate line  202  is connected with all gate electrodes  34  of the sub pixel units in the same row. A data line  203  is provided between two adjacent columns of sub pixel units. It should be noted that the data line  203  which is provided in this embodiment is only for illustration purpose, and the embodiments of the disclosure are not limited to this kind of configuration. 
     For example, vertical projections of the first drain electrode  32 , the second drain electrode  33 , the first extension electrode  11  and the second extension electrode  21  on the substrate  201  are not overlapped with a vertical projection of the gate line  202  on the substrate  201 . 
     For example, a first common electrode line  204  and a second common electrode line  205  are provided between the first pixel electrode  1  and the second pixel electrode  2  of each sub pixel unit which belongs to a same row. The first common electrode line  204  is close to the first pixel electrode  1 . The first common electrode line  204  and the second common electrode line  205  respectively include extension parts which are extended toward each other, such as an extension part  2041  of the first common electrode line  204  and an extension part  2051  of the second common electrode line  205 . A vertical projection of the extension part  2041  of the first common electrode line  204  on the substrate  201  and the vertical projection of the first extension electrode  11  on the substrate  201  are partially overlapped or completely overlapped, and a vertical projection of the extension part  2051  of the second common electrode line  205  on the substrate  201  and the vertical projection of the second extension electrode  21  on the substrate  201  are partially overlapped or completely overlapped. 
     For example, a vertical projection of the first common electrode line  204  on the substrate  201  and vertical projections of the gate line  202  and the gate electrode  34  on the substrate  201  are not overlapped, and a vertical projection of the second common electrode line  205  on the substrate  201  and the vertical projections of the gate line  202  and the gate electrode  34  on the substrate  201  are not overlapped. 
     It should be noted that the pixel structure provided by the embodiments of the disclosure includes two sub pixel electrodes (for example, the first pixel electrode  1  and the second pixel electrode  2 ). This pixel structure can also be modified, so that it can include three, four or more sub pixel electrodes. Of course, the pixel structure including a plurality of sub pixel electrodes should meet the following conditions: a plurality of drain electrodes of the pixel structure including the plurality of sub pixel electrodes are electrically connected to extension electrodes of the plurality of sub pixel electrodes respectively, the source electrodes are designed based on connection locations between respective drain electrodes and respective extension electrodes, and the connection locations between respective drain electrodes and respective extension electrodes are not overlapped with the vertical projection of the gate line. Similar description will not be repeated here. 
     In addition, in the embodiments of the disclosure, a vertical projection is an orthogonal projection along a direction perpendicular to the substrate  201 . 
     Beneficial effects of the embodiments of the disclosure include the following: the first pixel electrode and the second pixel electrode have extension electrodes which extend toward each other respectively, the first drain electrode and the second drain electrode are electrically connected with the corresponding extension electrodes respectively; the source electrode includes the first opening and the second opening, the first drain electrode and the second drain electrode can extend into corresponding openings along a horizontal direction from respective connections between respective drain electrodes and respective extension electrodes, which causes the TFT to have a larger area, i.e., the driving ability of the TFT is improved; the region between the first pixel electrode and the second pixel electrode can be effectively used by the above mentioned designs, so that the display region of the sub pixel unit will not be occupied by the first drain electrode and the second drain electrode, thereby improving a pixel aperture ratio of the sub pixel unit while the driving ability of the TFT is improved. 
     An embodiment of the disclosure provides a display panel, which includes the array substrate provided by the above mentioned embodiment. For example, the display panel is a liquid display panel or an OLED (Organic Light-Emitting Diode) display panel, etc. 
     Beneficial effects of the embodiment of the disclosure include the following: the first pixel electrode and the second pixel electrode have extension electrodes which extend toward each other respectively, the first drain electrode and the second drain electrode are electrically connected with the corresponding extension electrodes respectively; the source electrode includes the first opening and the second opening, and the first drain electrode and the second drain electrode can extend into corresponding openings along a horizontal direction from respective connections between respective drain electrodes and respective extension electrodes, which causes the TFT to have a larger area, i.e., the driving ability of the TFT is improved; the region between the first pixel electrode and the second pixel electrode can be effectively used by the above mentioned designs, so that the display region of the sub pixel unit will not be occupied by the first drain electrode and the second drain electrode, thereby improving a pixel aperture ratio of the sub pixel unit while the driving ability of the TFT is improved. 
     An embodiment of the disclosure provides a display device, which includes the display panel provided by the above mentioned embodiment. The display device can be a liquid crystal display device, an OLED display device, an electronic paper, a cell phone, a panel computer, a television set, a display, a laptop computer, a digital photo frame, a navigation equipment and any product or component which has a display function. 
     Beneficial effects of the embodiment of the disclosure include the following: the first pixel electrode and the second pixel electrode have extension electrodes which extend toward each other respectively, the first drain electrode and the second drain electrode are electrically connected with the corresponding extension electrodes respectively; the source electrode includes the first opening and the second opening, and the first drain electrode and the second drain electrode can extend into corresponding openings along a horizontal direction from respective connections between respective drain electrodes and respective extension electrodes, which causes the TFT to have a larger area, i.e., the driving ability of the TFT is improved; the region between the first pixel electrode and the second pixel electrode can be effectively used by the above mentioned designs, so that the display region of the sub pixel unit will not be occupied by the first drain electrode and the second drain electrode, thereby improving a pixel aperture ratio of the sub pixel unit while the driving ability of the TFT is improved. 
     The above embodiments of the disclosure are merely illustrative, and not used to limit the protection scope of the disclosure. The protection scope of the disclosure is determined by appended claims. 
     This application claims the priority of Chinese Patent Application No. 201520012777.X filed on Jan. 8, 2015, which is incorporated entirely herein by reference as a part of this application.