Patent Abstract:
Methods for controlling display panels, in which the display panel comprises a plurality of pixels and wherein each of the plurality of pixels comprises a plurality of sub-pixels, are provided. A representative the method comprises: controlling a timing sequence for turning on the pixels such that at least one of: an average influence of coupling of each of the sub-pixels in two sequential time frames is the same; and an average influence of coupling of two of the sub-pixels on two adjacent rows of the sub-pixels is the same.

Full Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to controlling of pixels of display devices.  
         [0003]     2. Description of Related Art  
         [0004]      FIG. 1  is a schematic view of a conventional liquid crystal display (LCD). As shown in  FIG. 1 , a conventional LCD panel  100  generally includes a gate driver  102 , a source driver  104  and a display area  106 . The display area  106  includes a pixel array constructed by a plurality of pixels. For example, a conventional display area with 1024×768 resolution has 1024 columns and 768 rows of pixels, such as the pixels  112 ,  114 ,  126 ,  122 ,  124 ,  126  and so on shown in  FIG. 1 . In addition, each pixel has a red sub-pixel, a green sub-pixel and a blue sub-pixel. For example, the pixel  112  in the first row and first column of the display area  106  has a red sub-pixel  112   r,  a green sub-pixel  112   g,  and a blue sub-pixel  112   b.  Therefore, the display area  106  has 3072 columns and 768 rows of sub-pixels.  
         [0005]     In  FIG. 1 , each sub-pixel has a thin film transistor (TFT) and a capacitor, wherein the capacitor is connected between the drain of the TFT and the common electrode. The gate of each TFT is connected to and controlled by the gate driver  102  via a corresponding scan line. In addition, the source of the TFT is connected to and controlled by the source driver  104  via a corresponding data line. Conventionally, the gate driver  102  generates a plurality of scan signals that are provided to the scan lines. Therefore, when one of the scan lines (e.g., the first scan line) receives the scan signal, all the TFTs connected to the first scan line (e.g., the TFTs of the sub-pixels  112   r ,  112   g ,  112   b ,  114   r ,  114   g ,  114   b  and so on) will be turned on, and the data signals may be stored in the capacitors connected to the TFTs.  
         [0006]     Conventionally, the number of the source lines of the display area is three times the number of the pixels in each column of the display area since each pixel of the display area has three sub-pixels (e.g., as described above, the 1024×768 resolution display area has 3072 scan lines). In addition, the total pin number of the integrated circuit (IC) of the source driver has to be equal to or greater than the number of the source lines. Therefore, the bonding between the scan lines of the conventional display area and the pins of the source driver is complex and time consuming. Accordingly, it is important to reduce the number of the source lines of the display area and the pin number of the source driver.  
         [0007]      FIG. 2  is a schematic view of another conventional LCD device. As shown in  FIG. 2 , LCD device  200  comprises a gate driver device  202 , a source driver device  204  and a display area  206 . The display area  206  comprises a multiplexer device  208  and a plurality of pixels such as  212 ,  214 ,  216 ,  218 ,  220 ,  222 ,  232 ,  234 ,  236 ,  238 ,  240 ,  242 , and so on. Moreover, each pixel of the display area comprises a red sub-pixel, a green sub-pixel and a blue sub-pixel. For example, the pixel  216  comprises a red sub-pixel  216   r , a green sub-pixel  216   g  and a blue sub-pixel  216   b.    
         [0008]     The multiplexer device  208  is disposed in the display area and connected between the data lines of the sub-pixels and the pins of the source driver device  204 . The multiplexer device  208  comprises a plurality of multiplexers such as multiplexers  222 ,  224 ,  226  and so on. Each multiplexer comprise  6  switches. For example, the multiplexer  224  comprises transistors  224   a ,  224   b ,  224   c ,  224   d ,  224   e  and  224   f , wherein the source (or drain) of the transistors  224   a ,  224   b ,  224   c ,  224   d ,  224   e  and  224   f  may be connected to the drain of TFTs of the sub-pixels  216   r ,  216   g ,  216   b ,  218   r ,  218   g  and  218   b  via the corresponding data lines  
         [0009]     However, for any two adjacent sub-pixels, the one that is turned on later in time may be electrically coupled to the other. Therefore, the charges stored in the capacitor of the sub-pixel that is turned on later in time may be influenced by the other sub-pixel. Accordingly, because a typical turn on sequence controlled by the control device  210  of the prior art is RGBRGB, i.e., the turn on sequence is started from transistor  224   a , sequentially followed by transistors  224   b ,  224   c ,  224   d ,  224   e  and  224   f , the coupled charge on the capacitor of sub-pixel  216   r  may be twice as much as those on the capacitor of sub-pixels  216   g ,  216   b ,  218   r  and  218   g , and the coupled charge on the capacitor of sub-pixel  218   b  is zero. Unfortunately, the different coupled charges between the same colored sub-pixels (for example,  216   r  and  218   r ) can make the display non-uniform even when displaying a pure color.  
       SUMMARY OF THE INVENTION  
       [0010]     Methods for controlling display panels, in which the display panel comprises a plurality of pixels and wherein each of the plurality of pixels comprises a plurality of sub-pixels, are provided. An exemplary embodiment of such a method comprises: controlling a timing sequence for turning on the pixels such that at least one of: an average influence of coupling of each of the sub-pixels in two sequential time frames is the same; and an average influence of coupling of two of the sub-pixels on two adjacent rows of the sub-pixels is the same.  
         [0011]     Devices also are provided. In this regard, an exemplary embodiment of such a device comprises: a display device comprising a plurality of pixels, each of the plurality of pixels having sub-pixels, the display device being operative to illuminate the sub-pixels in accordance with a timing sequence, the timing sequence being configured such that at least one of: an average influence of coupling of each of the sub-pixels in two sequential time frames is the same; and an average influence of coupling of two of the sub-pixels on two adjacent rows of the sub-pixels is the same.  
         [0012]     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
         [0014]      FIG. 1  is a schematic view of a conventional liquid crystal display device.  
         [0015]      FIG. 2  is a schematic view of another conventional liquid crystal display device.  
         [0016]      FIG. 3A  is a schematic view of a liquid crystal display device according to one embodiment of the present invention.  
         [0017]      FIG. 3B  and  FIG. 3C  are timing diagrams of a driving method of the sub-pixels according to one embodiment of the present invention.  
         [0018]      FIG. 4A  and  FIG. 4B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention.  
         [0019]      FIG. 5A  and  FIG. 5B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention.  
         [0020]      FIG. 6A  and  FIG. 6B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention.  
         [0021]      FIG. 7A  and  FIG. 7B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention.  
         [0022]      FIG. 8A  and  FIG. 8B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention.  
         [0023]     FIG. 9  is a block diagram of an electronic device according to one embodiment of the present invention. 
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0024]     The present invention will be described more fully hereinafter with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout.  
         [0025]     Refer to  FIG. 3 , which is a schematic view of a liquid crystal display device according to one embodiment of the present invention. In the embodiment, the liquid crystal display device  300  includes a control device  310  operated in a driving method different from the control device  200 , a corresponding gate driver device  302 , a source driver device  304  and a display area  206  that includes the same pixel architecture as the display area  206  shown in the  FIG.2 . With the driving method described below, the liquid crystal display device  300  could provide improvements in image uniformity.  
         [0026]      FIG. 3B  and  FIG. 3C  are timing diagrams of a driving method of the sub-pixels according to one embodiment of the present invention. For example, in any one of the scan lines (e.g., the first scan line), the timing sequence for turning on the TFTs in an N th  frame is shown as  FIG. 3B , and in an N+1 th  frame is shown as  FIG. 3C . Referring to  FIG. 3B , it is noted that the 6 sub-pixels of two adjacent pixels that are connected to the same multiplexer may be turned on for storing the corresponding data signals as a sequence of sub-pixels R 1 , G 1 , B 1 , R 2 , G 2  and B 2 . For example, the sub-pixels R 1 , G 1 , B 1  may represent the red, green and blue sub-pixels of the left side pixel (e.g., the pixel  212 / 216 / 220 ), and the sub-pixels R 2 , G 2 , B 2  may represent the red, green and blue sub-pixels of the right side pixel (e.g., the pixel  214 / 218 / 222 ).  
         [0027]     In  FIG. 3B , the sub-pixels in the N th  frame may turned on as a sequence of R 1 , G 1 , B 1 , R 2 , G 2 , B 2 . It should be noted that, for any two adjacent sub-pixels, the one that is turned on later may be electrically coupled to the other. Therefore, the charges stored in the capacitor of the sub-pixel that is turned on later may be influenced by the other sub-pixel, wherein the amount of the influence is denoted as D. For example, sub-pixel  216   r  is electrically coupled to sub-pixels  214   b  and  216   g . Sub-pixels  214   b  and  214   g  are turned on after sub-pixel  216   r  (indicated by the arrow from sub-pixels  214   b  to  216   r  and the arrow from sub-pixels  216   g  to  216   r ). Thus, the amount of the influence of the coupling of the sub-pixel  216   r  is represented as  2 D. In addition, the sub-pixels  216   g / 216   b / 218   r / 218   g  are electrically coupled to the sub-pixels  216   b / 218   r / 218   g / 218   b . The amount of the influence of the coupling of the sub-pixels  216   g / 216   b / 218   r / 218   g  is represented as D. Moreover, the sub-pixel  218   b  is turned on latest, and thus is not electrically coupled to any other sub-pixel. Thus, the amount of the influence of the coupling of the sub-pixel  218   b  is 0.  
         [0028]     As described above, the amounts of the influence of the coupling of the red sub-pixels  212   r ,  214   r ,  216   r ,  218   r ,  220   r  and  222   r  in the N th  frame are  2 D, D,  2 D, D,  2 D, D, respectively. Therefore, the brightness of the red sub-pixels in the whole LCD panel is not uniform. In addition, the amounts of the influence of the coupling of the blue sub-pixels  212   b ,  214   b ,  216   b ,  218   b ,  220   b  and  222   b  in the N th  frame are D,  0 , D,  0 , D,  0 , respectively. Thus, the brightness of the blue sub-pixels in the whole LCD panel is also not uniform.  
         [0029]     Referring to  FIG. 3C , in the N+1 th  frame, the timing sequence of the sub-pixels R 1 , G 1 , B 1 , R 2 , G 2  and B 2  is changed to be different from the N th  frame. In particular, in this embodiment, the sequence for turning on the TFTs is B 2 , G 2 , R 2 , B 1 , G 1  and R 1 . Accordingly, the amounts of the influence of the coupling of the sub-pixels  216   r ,  216   g ,  216   b ,  218   r ,  218   g  and  218   b  in the N th  frame as shown in  FIG. 3B  are  2 D, D, D, D, D,  0 , respectively and in the N+1 th  frame as shown in  FIG. 3C  are  0 , D, D, D, D,  2 D, respectively. Therefore, the average influences of the coupling of any two red sub-pixels, for example, the sub-pixels  216   r  and  218   r  in two adjacent frames, are the same. In addition, the average influences of the coupling of any two blue sub-pixels, for example, the sub-pixels  216   b  and  218   b  in two adjacent frames, are the same. Thus, the average brightness of any red/green/blue sub-pixels of the LCD panel in two adjacent frames is uniform.  
         [0030]     In one embodiment of the present invention, the timing sequence for turning on the TFTs of the sub-pixels  212   b ,  214   b ,  216   b ,  218   b ,  220   b  and  222   b , for example, the sequence R 1 , G 1 , B 1 , R 2 , G 2  and B 2  shown in  FIG. 3B , and the sequence B 2 , G 2 , R 2 , B 1 , G 1  and R 1  shown in  FIG. 3C  is controlled by the control device  310  shown in  FIG. 3A .  
         [0031]      FIG. 4A  and  FIG. 4B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention. For example, in any frame, the timing sequence for turning on the TFTs connected to the M th  scan line is shown as  FIG. 4A , and the timing sequence for turning on the TFTs connected to the M+1 th  scan line is shown as  FIG. 4B . Accordingly, the amounts of the influence of the coupling of the sub-pixels, for example, the sub-pixels  216   r ,  216   g ,  216   b ,  218   r ,  218   g  and  218   b  of the first scan line as shown in  FIG. 4A  are  2 D, D, D, D, D,  0 , respectively and that of the sub-pixels  236   r ,  236   g ,  236   b ,  238   r ,  238   g  and  238   b  of the second scan line that is adjacent to the first scan line as shown in  FIG. 4B  are  0 , D, D, D, D,  2 D, respectively. Therefore, in any frame, the average influences of the coupling of any two adjacent red sub-pixels, for example, the sub-pixel  216   r  on the M th  scan line and the sub-pixels  236   r  on the M+1 th  scan line, are the same. In addition, the average influences of the coupling of any two adjacent blue sub-pixels, for example, the sub-pixel  216   b  on the M th  scan line and the sub-pixel  236   b  on the M+1 th  scan line, are the same. Thus, the average brightness of two red/green/blue sub-pixels of the LCD panel on two adjacent scan lines is uniform.  
         [0032]      FIG. 5A  and  FIG. 5B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention. For example, the timing sequence for turning on the TFTs connected to the M th  and M+1 th  scan lines in the N th  frame is shown as  FIG. 5A , and the timing sequence for turning on the TFTs connected to the M th  and M+1 th  scan lines in the N+1 th  frame is shown as  FIG. 5B . Accordingly, in the N th  and N+1 th  frames, the average influences of the coupling of two red, green or blue sub-pixels on any two scan lines (i.e., the M th  and M+1 th  scan lines) are the same. In addition, the average influences of the coupling of any red, green or blue sub-pixels in any two adjacent frames are the same. Thus, the average brightness of two red/green/blue sub-pixels of the LCD panel on two adjacent scan lines is uniform, and the average brightness of any red/green/blue sub-pixels of the LCD panel in two adjacent frames is also uniform.  
         [0033]      FIG. 6A  and  FIG. 6B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention. For example, in any one of the scan lines (e.g., the first scan line), the timing sequence for turning on the TFTs connected to the first scan line in an N th  frame is shown as  FIG. 6A , and in a next N+1 th  frame is shown as  FIG. 6B . The sequence for turning on the TFTs of the sub-pixels shown in  FIG. 6A  may comprise R 1 , G 1 , B 1 , R 2 , G 2  and B 2 , and that of the sub-pixels shown in  FIG. 6B  may comprise R 2 , G 2 , B 2 , R 1 , G and B 1 . Accordingly, the amounts of the influence of the coupling of the sub-pixels  216   r ,  216   g ,  216   b ,  218   r ,  218   g  and  218   b  in the N th  frame as shown in  FIG. 6A  are  2 D, D, D, D, D,  0 , respectively and in the N+1 th  frame as shown in  FIG. 6B  are D, D,  0 ,  2 D, D, D, respectively. Therefore, the average influences of the coupling of any two red sub-pixels, for example, the sub-pixels  216   r  and  218   r  in two adjacent frames, are the same. In addition, the average influences of the coupling of any two blue sub-pixels, for example, the sub-pixels  216   b  and  218   b  in two adjacent frames, are the same. Thus, the average brightness of any red/green/blue sub-pixels of the LCD panel in two adjacent frames is uniform.  
         [0034]      FIG. 7A  and  FIG. 7B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention. For example, in any frame, the timing sequence for turning on the TFTs connected to the M th  scan line is shown as  FIG. 7A , and the timing sequence for turning on the TFTs connected to the M+1 th  scan line is shown as  FIG. 7B . Accordingly, the amounts of the influence of the coupling of the sub-pixels, for example, the sub-pixels  216   r ,  216   g ,  216   b ,  218   r ,  218   g  and  218   b  of the first scan line as shown in  FIG. 7A  are  2 D, D, D, D, D,  0 , respectively and that of the sub-pixels  236   r ,  236   g ,  236   b ,  238   r ,  238   g  and  238   b  of the second scan line that adjacent to the first scan line as shown in  FIG. 7B  are D, D,  0 ,  2 D, D, D, respectively. Therefore, in any frame, the average influences of the coupling of any two adjacent red sub-pixels, for example, the sub-pixel  216   r  on the M th  scan line and the sub-pixels  236   r  on the M+1 th  scan line, are the same. In addition, the average influences of the coupling of any two adjacent blue sub-pixels, for example, the sub-pixel  216   b  on the M th  scan line and the sub-pixel  236   b  on the M+1 th  scan line are, the same. Thus, the average brightness of two red/green/blue sub-pixels of the LCD panel on two adjacent scan lines is uniform.  
         [0035]      FIG. 8A  and  FIG. 8B  are timing diagrams of a driving method of the sub-pixels according to another embodiment of the present invention. For example, the timing sequence for turning on the TFTs connected to the M th  and M+1 th  scan lines in the N th  frame is shown as  FIG. 8A , and the timing sequence for turning on the TFTs connected to the M th  and M+1 th  scan lines in the N+1 th  frame is shown as  FIG. 8B . A Accordingly, in the N th  and N+1 th  frames, the average influences of the coupling of two red, green or blue sub-pixels on any two scan lines (i.e., the M th  and M+1 th  scan lines) are the same. In addition, the average influences of the coupling of any red, green or blue sub-pixels in any two adjacent frames are the same. Thus, the average brightness of two red/green/blue sub-pixels of the LCD panel on two adjacent scan lines is uniform, and the average brightness of any red/green/blue sub-pixels of the LCD panel in two adjacent frames is also uniform.  
         [0036]     Referring to  FIG. 9 , a block diagram of an embodiment of an electronic device  90  is depicted. The electronic device  90  comprises a display device  92  and an input device  94 . The input device  94  generates display data to the data driver  920 . Accordingly, data driver  920  can send the display data to the display area  900  with proper operation of scan driver  910 . Notably, the display device  92  uses a driving method such as provided in one of the embodiments described above.  
         [0037]     Accordingly, an average influence of coupling of each of the sub-pixels in two adjacent frames is the same, and/or an average influence of coupling of two of the sub-pixels on two adjacent scan lines is the same by controlling the timing sequence. Thus, the average brightness of any red/green/blue sub-pixels of the LCD panel in two adjacent frames is uniform.  
         [0038]     It will be apparent to those skilled in the art that various modifications and variations can be made to the above described embodiments without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Technology Classification (CPC): 6