Patent Publication Number: US-10777161-B2

Title: Array substrate, liquid crystal display panel and display device

Description:
RELATED APPLICATION 
     The present application is the U.S. national phase entry of PCT/CN2017/091040, with an international filing date of Jun. 30, 2017, which claims the benefit of Chinese Patent Application No. 201610935519.8 filed on Nov. 1, 2016, the entire disclosures of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to the technical field of liquid crystal display, in particular to an array substrate, a liquid crystal display panel and a display device. 
     BACKGROUND 
     In a liquid crystal display panel, in order to avoid deterioration of the quality of liquid crystal molecules and bad display caused by a long time fixed voltage, signals provided to data lines in the display panel must undergo a polarity reversal. The polarity reversal drive of the panel usually includes point reversal, row reversal, column reversal, etc., wherein the column reversal has the smallest power consumption, so it is widely applied to panels of low logic power consumption. 
     During column reversal, signals on adjacent data lines have opposite polarities, so charge consumption for performing polarity reversal of the signals on the data lines can be reduced by means of charge sharing between adjacent data lines, thereby reducing power consumption. However, a charge sharing device generally has complex circuits, and key elements must be integrated on the IC, so the cost and volume of the IC are greatly increased. 
     SUMMARY 
     Therefore, it is desirable to provide an apparatus that can help to solve some or all of the above-mentioned problems. 
     According to a first aspect of the present disclosure, an array substrate is provided, which has a display area and a non-display area in the periphery of the display area, and comprises: a plurality of gate lines to which gate pulse signals are provided; a plurality of data lines to which data signals are provided, wherein signals on adjacent ones of said plurality of data lines have opposite polarities; a charge sharing device comprising a first thin film transistor in the non-display area, a first terminal of said first thin film transistor being connected to one of two adjacent data lines among said plurality of data lines, a second terminal thereof being connected the other of the two adjacent data lines, and a gate thereof being configured to be provided with a first control signal in a blank time period between adjacent data frames so as to turn on said first thin film transistor. 
     In certain exemplary embodiments, said first control signal comprises a frame turn-on signal or a turn-on signal for a gate driver. 
     In certain exemplary embodiments, said plurality of gate lines further includes a first dummy gate line in the non-display area, and wherein the gate of the first thin film transistor is connected to said first dummy gate line, and the first control signal is a gate pulse signal on said first dummy gate line. 
     In certain exemplary embodiments, said first dummy gate line is at a side of said plurality of data lines close to a source driver for providing data signals to said plurality of data lines. 
     In certain exemplary embodiments, said charge sharing circuit further includes a second thin film transistor in the non-display area, a first terminal of said second thin film transistor being connected to one of the two adjacent data lines, a second terminal thereof being connected the other of the two adjacent data lines, and a gate thereof being configured to be provided with a second control signal in a blank time period between adjacent data frames so as to turn on said second thin film transistor. 
     In certain exemplary embodiments, said second control signal comprises a frame turn-on signal or a turn-on signal for the gate driver. 
     In certain exemplary embodiments, said plurality of gate lines further includes a second dummy gate line in the non-display area, and wherein the gate of the second thin film transistor is connected to said second dummy gate line, and the second control signal is a gate pulse signal on said second dummy gate line. 
     In certain exemplary embodiments, said second dummy gate line is at a side of said plurality of data lines far away from the source driver for providing data signals to said plurality of data lines. 
     In certain exemplary embodiments, under the condition that the scanning direction for the gate lines is from the side of said plurality of data lines close to the source driver to the side far away from the source driver, said first dummy gate line is provided with a gate pulse signal prior to other gate lines. 
     In certain exemplary embodiments, under the condition that the scanning direction for the gate lines is from the side of said plurality of data lines far away from the source driver to the side close to the source driver, said second dummy gate line is provided with a gate pulse signal prior to other gate lines. 
     In certain exemplary embodiments, the first terminal and the second terminal of the first thin film transistor may adopt a U-shape structure and may be intersected with each other. 
     In certain exemplary embodiments, under the condition that there is a stage formed by the thin film transistor between any two adjacent data lines among said plurality of data lines, the first terminal of the first thin film transistor is connected to a second terminal of an adjacent previous stage thin film transistor, and the second terminal of the first thin film transistor is connected to a first terminal of an adjacent next stage thin film transistor. 
     In certain exemplary embodiments, the first thin film transistor can be located between a fan-shaped wiring area and the source driver. 
     In certain exemplary embodiments, the first thin film transistor can be located between the fan-shaped wiring area and the display area. 
     The array substrate provided in the present disclosure can realize optimal charge sharing effect without increasing the circuit design cost, thereby achieving the effect of saving power consumption. 
     According to a second aspect of the present disclosure, a liquid crystal display panel is provided, which comprises any of the above-mentioned charge sharing device. 
     According to a third aspect of the present disclosure, a display device is provided, which comprises the above-mentioned liquid crystal display panel. 
     These and other advantages of the present disclosure will become clearer from the embodiments described below, and will be depicted with reference to the embodiments described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will now be described in further detail with reference to the drawings. The same or similar reference numerals indicate the same or similar elements throughout the drawings. In the drawings: 
         FIG. 1A  shows an array substrate according to a first embodiment of the present disclosure; 
         FIG. 1B  shows an array substrate according to a second embodiment of the present disclosure; 
         FIG. 1C  shows an array substrate according to a third embodiment of the present disclosure; 
         FIG. 1D  shows an array substrate according to a fourth embodiment of the present disclosure; 
         FIG. 2  shows an array substrate according to a fifth embodiment of the present disclosure; 
         FIGS. 3A-3C  are structural diagrams of a first thin film transistor in a shared switch of the array substrate according to the present disclosure; 
         FIG. 4  generally shows a sequence diagram of signals on respective signal lines on the array substrate according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Specific details are provided in the text below for facilitating a full understanding and for enabling the various embodiments of the present disclosure. Those skilled in the art shall understand that the technical solutions of the present disclosure can be implemented in a case where many of said details are missing. In some circumstances, well known structures and functions are not shown or described in detail in order not to unnecessarily blur the descriptions of the embodiments of the present disclosure. It is anticipated that terms used in this disclosure should be understood in the broadest reasonable way, even if they are used in conjunction with detailed descriptions of specific embodiments of the present disclosure. 
       FIG. 1A  shows an array substrate  100  according to a first embodiment of the present disclosure. As shown in  FIG. 1A , said array substrate  100  has a display area bounded by a display area outer frame  101  and a non-display area that is in the periphery of the display area and is bounded by an array substrate outer frame  102 . Said array substrate further comprises a plurality of gate lines to which gate pulse signals are provided and a plurality of data lines to which data signals are provided, wherein signals on adjacent data lines among said plurality of data lines have opposite polarities. Said plurality of data lines and said plurality of gate lines are intersected with each other. For the sake of simplicity and clarity,  FIG. 1A  only shows two gate lines  107  and  108  and two adjacent data lines  109  and  110 . It should be understood that although  FIG. 1  only shows two gate lines in the non-display area, there are still several gate lines (not shown) that cross the display area and intersect with said plurality of data lines. Said gate pulse signals are provided by a gate driver  104 , and said data signals are provided by a source driver  103 . The array substrate further comprises a charge sharing device, which comprises a first thin film transistor  111  outside of the display area of the array substrate. A first terminal of the first thin film transistor  111  can be connected to a data line  109 , a second terminal thereof can be connected to a data line  110 , and a gate thereof is provided with a first control signal. Said first control signal is provided in a blank time period between adjacent data frames so as to turn on said first thin film transistor. After turning on said first thin film transistor, charges are shared between adjacent data lines  109  and  110 . 
     As shown in  FIG. 1A , a gate of the first thin film transistor  111  can be connected to a STV signal line  106 , and the STV signal line  106  is connected to the source driver  103 . In this embodiment, said source driver  103  is outside of the display area and provides a frame turn-on signal to the gate of the first thin film transistor  111  through the STV signal line  106 . The frame turn-on signal is in the blank time period between adjacent data frames. Thus, by providing the frame turn-on signal to the gate of the first thin film transistor  111 , the first thin film transistor can be turned on in the blank time period between adjacent data frames. 
     In  FIG. 1A , the first thin film transistor  111  is at a side of the adjacent data lines close to the source driver  103 , i.e. a proximal side. Further, in this case, the first thin film transistor may be located in an area between the fan-shaped wiring area and the source driver. The fan-shaped wiring area is known in the art, so it will not be elaborated herein. The area between the fan-shaped wiring area and the source driver has a small space, so it is suitable for a small thin film transistor so as to utilize the wiring space more reasonably, as shown in  FIG. 3C . In certain exemplary embodiments, the first thin film transistor may also be located in an area between the display area and the fan-shaped wiring area. Since the area between the display area and the fan-shaped wiring area is large, a large thin film transistor can be used and passage of a large current is allowed, accordingly, a better effect of charge sharing can be achieved, as shown in  FIG. 3B . Of course, said first thin film transistor  111  can also be at a side of said adjacent data lines far away from the source driver  103 , i.e. a distal side. 
     Said source driver  103  can also be connected to the gate driver  104  so as to provide a turn-on signal for the gate driver thereto. It should be pointed out that the gate of the first thin film transistor  111  may alternatively be provided with the turn-on signal for the gate driver so as to turn on said first thin film transistor in the blank time period between adjacent data frames. In this case, said source driver  103  can provide the turn-on signal for the gate driver to the gate of the first thin film transistor  111  through the STV signal line  105  connected to the source driver  103 , as will be described below with reference to  FIG. 1B . In certain exemplary embodiments, one or more of said gate lines can be dummy gate lines, as will be described below. 
     It should be pointed out that the above embodiment of the array substrate is only described as an example. In other embodiments, the charge sharing device in said array substrate may comprise two or more first thin film transistors arranged in the way described above, and the larger the number of the first thin film transistors, the better the effect of charge sharing. 
       FIG. 1B  shows an array substrate  100  according to a second embodiment of the present disclosure. In  FIG. 1B , the gate of the first thin film transistor  111  is connected to the STV signal line  105 . As mentioned above, said STV signal line  105  is connected to the source driver  103 . Said source driver  103  is outside of the display area and provides a turn-on signal for the gate driver  104  to the gate of the first thin film transistor  111  through the STV signal line  105 . The turn-on signal for the gate driver  104  is in the blank time period between adjacent data frames. Thus, by providing the turn-on signal for the gate driver to the gate of the first thin film transistor  111 , the first thin film transistor can be turned on in the blank time period between adjacent data frames. 
     In  FIG. 1B , said first thin film transistor  111  is at a side of said adjacent data lines far away from the source driver  103 , i.e. a distal side. Of course, said first thin film transistor  111  can also be at a side of said adjacent data lines close to the source driver  103 , i.e. a proximal side, as described in the above with reference to  FIG. 1A . 
     It should be noted that the above embodiment of the array substrate is only described as an example. In other embodiments, the charge sharing device in said array substrate may comprise two or more first thin film transistors arranged in the way described above, and the larger the number of the first thin film transistors, the better the effect of charge sharing. 
       FIG. 1C  shows an array substrate  100  according to a third embodiment of the present disclosure. In  FIG. 1C , the gate line  107  is a first dummy gate line. Gate pulse signals provided on the first dummy gate line are not used as scanning signals for igniting the liquid crystal cells, but they only function to stabilize the gate pulse signals. Before or after providing all conventionally set gate lines (e.g. within the display area) with gate pulse signals that are used as scanning signals for igniting the liquid crystal cells, said first dummy gate line is provided with gate pulse signals. The gate of the first thin film transistor  111  is connected to the first dummy gate line  107 . In this case, the first control signal can be the gate pulse signal on the first dummy gate line  107 . The gate pulse signal on the first dummy gate line  107  is in the blank time period between adjacent data frames. Thus, by providing the gate pulse signal on the first dummy gate line  107  to the gate of the first thin film transistor  111 , the first thin film transistor can be turned on in the blank time period between adjacent data frames. 
     In  FIG. 1C , the first thin film transistor  111  and the gate line  107  are both at the side of the adjacent data lines far away from the source driver  103 , i.e. the distal side. Alternatively, in this case, when the scanning direction for the gate lines is from the distal side to the side close to the source driver  103  (i.e. the proximal side), said first dummy gate line  107  is provided with gate pulse signals prior to other gate lines. Of course, the first thin film transistor  111  and the gate line  107  can also be at the proximal side. 
     It should be noted that the above embodiment of the array substrate is only described as an example. In other embodiments, the charge sharing device in said array substrate may comprise two or more first thin film transistors arranged in the way described above, and the larger the number of the first thin film transistors, the better the effect of charge sharing. 
       FIG. 1D  shows an array substrate  100  according to a fourth embodiment of the present disclosure. As shown in  FIG. 1D , the gate line  108  is a first dummy gate line. The gate of the first thin film transistor  111  can be connected to said first dummy gate line  108 . In this case, the first control signal can be the gate pulse signal on said first dummy gate line  108 . The gate pulse signal on said first dummy gate line  108  is in the blank time period between adjacent data frames. Thus, by providing the gate pulse signal on said first dummy gate line to the gate of the first thin film transistor  111 , the first thin film transistor can be turned on in the blank time period between adjacent data frames. 
     In  FIG. 1D , the first thin film transistor  111  and the gate line  108  are both at the side of the adjacent data lines close to the source driver  103 , i.e. the proximal side. Alternatively, in this case, when the scanning direction for the gate lines is from the proximal side to the side far away from the source driver  103  (i.e. the distal side), said first dummy gate line  108  is provided with gate pulse signals prior to other gate lines. Of course, the first thin film transistor  111  and the gate line  108  can also be at the distal side. 
     It should be pointed out that the above embodiment of the array substrate is only described as an example. In other embodiments, the charge sharing device in said array substrate may comprise two or more first thin film transistors arranged in the way described above, and the larger the number of the first thin film transistors, the better the effect of charge sharing. 
     It should be noted that the elements in  FIGS. 1B, 1C and 1D  which are not described have the same function and arrangement as the corresponding elements in  FIG. 1A , so for the sake of simplicity, they will not be described herein. 
     It should also be noted that the thin film transistor mentioned above can be an N-type thin film transistor or a P-type thin film transistor, which is not limited herein. The first terminal of the thin film transistor as mentioned above can be a source or a drain, and correspondingly, the second terminal of the thin film transistor can be a drain or a source. 
     It should also be noted that although four types of charge sharing devices are described independently in embodiments of different array substrates in the above text, any two or more of said four array substrates can be combined in the embodiment of one array substrate. As an example, an exemplary array substrate is described below with reference to  FIG. 2 , in which a combination of all the above-mentioned four types of charge sharing devices is provided. 
       FIG. 2  shows an array substrate  100  according to a fifth embodiment of the present disclosure. As shown in  FIG. 2 , the charge sharing device of said array substrate comprises four thin film transistors  211 ,  212 ,  213  and  214  that are out of the display area of the array substrate. 
     A first terminal of the thin film transistor  211  is connected to a data line  109 , a second terminal thereof is connected to an adjacent data line  110  and a gate thereof is connected to the STV signal line  106 . The thin film transistor  211  is at the side of the adjacent data lines close to the source driver  103 . The STV signal line  106  can be connected to the source driver  103 . The source driver  103  is outside of the display area of the array substrate and provides a frame turn-on signal to the gate of the first thin film transistor  211  through the STV signal line  106 . 
     A first terminal of the thin film transistor  212  is connected to the data line  109 , a second terminal thereof is connected to the data line  110  and a gate thereof is connected to the STV signal line  105 . The thin film transistor  212  is at the side of the adjacent data lines far away from the source driver  103 . The STV signal line  105  can be connected to the source driver  103 . The source driver  103  provides a turn-on signal for the gate driver to the gate of the thin film transistor  212  through the STV signal line  105 . 
     A first terminal of the thin film transistor  213  is connected to the data line  109 , a second terminal thereof is connected to the data line  110  and a gate thereof is connected to the first dummy gate line  107 . The thin film transistor  213  and the first dummy gate line  107  are both at the side of the adjacent data lines of the adjacent data lines far away from the source driver  103 , i.e. the proximal side. The gate pulse signal on the first dummy gate line  107  is in the blank time period between adjacent data frames. Thus, by providing the gate pulse signal on the first dummy gate line  107  to the gate of the thin film transistor  213 , the thin film transistor  213  can be turned on in the blank time period between adjacent data frames. 
     A first terminal of the thin film transistor  214  is connected to the data line  109 , a second terminal thereof is connected to the data line  110  and a gate thereof is connected to the second dummy gate line  108 . The thin film transistor  214  and the second dummy gate line  108  are both at the side of the adjacent data lines far away from the source driver  103 , i.e. the distal side. The gate pulse signal on the second dummy gate line  108  is in the blank time period between adjacent data frames, so by providing the gate pulse signal on the second dummy gate line  108  to the gate of the thin film transistor  214 , the thin film transistor  214  can be turned on in the blank time period between adjacent data frames. 
     In the above embodiments, when the scanning direction for the gate lines is from the distal side to the proximal side, said first dummy gate line  107  is provided with gate pulse signals prior to other gate lines. When the scanning direction for the gate lines is from the proximal side to the distal side, said second dummy gate line  108  is provided with gate pulse signals prior to other gate lines. 
     It should be pointed out that the “first” in the first dummy gate line and the “second” in the second dummy gate line are not specific or restrictive, but they are only used for facilitating description. For example, the first dummy gate line and the second dummy gate line can be used interchangeably. 
       FIG. 3A  is a structural diagram of a first thin film transistor (TFT) in a shared switch of the array substrate according to the present disclosure. As shown in  FIG. 3A , a first terminal A of said TFT is connected to a data line with a positive polarity, and a second terminal B thereof is connected to an adjacent data line with a negative polarity. 
       FIG. 3B  is a structural diagram of a first thin film transistor (TFT) in a shared switch of the array substrate according to the present disclosure. As shown in  FIG. 3B , the first terminal and second terminal of the TFT may have a U-shape structure and may be intersected with each other. As shown in  FIG. 3B , a terminal indicated by A represents the first terminal of the TFT, and a terminal indicated by B represents the second terminal of the TFT, wherein both the first terminal and the second terminal have a U-shape structure and are intersected with each other. By means of such a structure, the size of the thin film transistor can be increased so as to allow passage of a large current. As a result, a better charge sharing effect can be achieved. 
       FIG. 3C  is a structural diagram of a first thin film transistor (TFT) in a shared switch of the array substrate according to the present disclosure. When there is a stage formed by the thin film transistor between any two adjacent data lines among a plurality of data lines, as shown in  FIG. 3C  and as an example, a second terminal B of the thin film transistor TFT_ 2  is connected to a data line with a positive polarity, and a first terminal A of said TFT_ 2  is connected to a second terminal of an adjacent TFT_ 1  or to an adjacent data line with a negative polarity through a conductor. As shown in  FIG. 3C , the first terminal of TFT_ 2  can be connected to a second terminal of an adjacent previous stage (left) TFT_ 1  through the conductor, and the second terminal of TFT_ 2  can be connected to a first terminal of an adjacent next stage (right) TFT_ 3  through the conductor. Of course, connecting through the conductor is merely an example, for instance, when two TFTs are close to each other, said connection can be a direction connection without using any conductor. By means of such a structure, a small thin film transistor can be used as the charge sharing device of the present disclosure. 
     It should be noted that the “connection” in this text usually refers to “electrical connection” unless otherwise specified. 
       FIG. 4  generally shows a sequence diagram of signals on respective signal lines on the array substrate according to the present disclosure. As shown in  FIG. 4 , the signal (STV signal) on the STV signal line is provided in time period t 1 . As mentioned above, said STV signal can be the frame turn-on signal or the turn-on signal for the gate driver. The gate pulse signal (dummy gate line signal) on the dummy gate line is provided in time period t 2 . In a following time period t 3 , conventional gate lines are provided with gate pulse signals (gate scanning signals). The time period t 3  is a time of charging for all pixels within one frame. In  FIG. 4 , said signals are all shown as high level signals Vgh when being provided, but this is only exemplary instead of being restrictive. In the figure, Vgl represents a low level. 
     It can be seen from  FIG. 4  that when signals on any adjacent data lines n and n+1 undergo a polarity reversal, after the charging sharing in time periods t 1  and t 2 , the potential of the signal on data line n is pulled from a low level Vdl to a charge sharing potential Vcom, for example, and a target potential of the signal on said data line n is a high level Vdh; while the potential of the signal on data line n+1 is pulled from the high level Vdh to the charge sharing potential Vcom, for example, and a target potential of the signals on said data line n+1 is the low level Vdl. Generally, the charge sharing potential Vcom is an intermediate value between the high level Vdh and the low level Vdl, i.e. a half of the sum of Vdh and Vdl. In this way, the time needed for reversing the potential of the signal on data line n to the target potential and reversing the potential of the signal on data line n+1 to the target potential can be reduced, thereby saving electrical power consumption. When inputting the next frame, signals on adjacent data lines n and n+1 can undergo a next polarity reversal in time periods t 4  and t 5 . 
     It should be noted that t 1 , t 2 , t 4  and t 5  in  FIG. 4  are all set in the frame blank time periods of the image display, in which time periods potential changes on the data lines will not influence gray scale signal writing for the display area pixels. 
     It should be understood that for the sake of clarity, embodiments of the present disclosure are described with reference to different units or components. However, it is apparent that the functionality of each functional unit can be implemented in a single unit, in multiple units or be implemented as a part of some other functional unit without departing from the content of the present disclosure. For example, a functionality described as being implemented by a single unit may be implemented by several different units. Thus, reference to a specific functional unit shall only be considered as reference to an appropriate unit for providing the described functionality, but it does not indicate any strict logical or physical structure or organization. 
     Although the present disclosure has been described in conjunction with some embodiments, the present disclosure is not limited to the specific ways described herein. The scope of the present disclosure shall only be defined by the appended claims. Additionally, individual features can be included in different claims, but said features can be combined to advantage, and the fact that said features are included in different claims does not mean that combination of them are infeasible and/or disadvantageous. The sequence of the features in the claims does not suggest any specific sequence that must be followed by the features. In addition, in the claims, the word “comprise” does not mean to exclude other elements, and the indefinite article “a” or “an” does not mean to exclude multiple. Reference signs used in the claims are only provided as explicit examples, but they should not be construed as limiting the claims in any way.