Abstract:
When electric current is provided to a scan line of a display panel, electric current flowing from an initial end to a final end of the scan line is gradually reduced because of resistance consumption, resulting in lower brightness on both left and right sides of the display panel. Therefore, data line driving signals provided to the display panel are compensated for solving such a problem.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is related to a display control system and a related method, and more particularly, to a display control system of a display panel and a related method. 
         [0003]    2. Description of the Prior Art 
         [0004]    An organic light-emitting diode (OLED) is a current-driven electric lighting element having a brightness that depends on the magnitude of a related current. At present, the magnitude of the brightness (which is also called the gray-scale value) is controlled by the magnitude of the OLED driving current in an application OLED matrix display. 
         [0005]    Please refer to  FIG. 1  and  FIG. 2 .  FIG. 1  is block diagram of a display control system  1  according to the prior art, and  FIG. 2  is a schematic diagram of a display panel  10  of the display control system  1 . The display control system  1  comprises the display panel  10 , an image control circuit  12 , and a driver circuit  14 . The image control circuit  12  generates data signals and scan signals, and the driver circuit  14  generates data line driving signals and scan line driving signals according to the data signals and the scan signals received from the image control circuit  12  to drive data lines  15  and scan lines  11  and  13  of the display panel  10 . As indicated in  FIG. 2 , the data lines  15  are approximately vertical with the scan lines  11  and  13 , and the scan lines  11  and the scan lines  13  are interlaced. In another case, the scan lines  11  and the scan lines  13  are not interlaced, and the scan lines  11  are positioned on the top half of the display panel  10  and the scan lines  13  are positioned on the bottom half of the display panel  10 . 
         [0006]    Please refer to  FIG. 2 . The scan lines  11  and the scan lines  13  are interlaced. Because of resistance consumption of the scan lines  11  and  13 , when a voltage is applied to the initial ends of the scan lines  11  and  13 , the magnitude of currents flowing through the scan lines  11  and  13  is reduced as the distances that the currents travel increases.  FIG. 3  illustrates the relationship between the distance and the magnitude of the currents flowing through the scan lines  11 , and  FIG. 4  illustrates the relationship between the distance and the magnitude of the currents flowing through the scan lines  13 . 
         [0007]    If the distribution of driving currents of OLEDs of one scan line is not uniform, it results in a defect in which the brightness of the display panel is unbalanced or that the brightness of the display panel near the right side and the left side of the display panel is less than a standard level. Especially in the fabrication of large-sized panels, the unbalanced brightness of the display panel may cause gray-scale value shifts between areas in the display panel, which considerably distorts the displayed image. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention discloses a display control system of a display panel. The display control system comprises an image control circuit for generating a data signal and a scan signal, a compensation circuit coupled to the image control circuit for generating a compensation signal according to the distribution and magnitude of currents flowing through scan lines of the display panel, and a driver circuit coupled to the image control circuit and the compensation circuit for outputting data line driving signals to data lines of the display panel according to the compensation signal and the data signal and for outputting scan line driving signals to the scan lines of the display panel according to the scan signal to drive the display panel to display images. 
         [0009]    The present invention also discloses a flat display. The flat display comprises a display panel for displaying images and a display control system. The display control system comprises an image control circuit coupled to the display panel for generating a data signal and a scan signal, a compensation circuit coupled to the image control circuit for generating a compensation signal according to the distribution and magnitude of currents flowing through scan lines of the display panel, and a driver circuit coupled to the display panel, the image control circuit, and the compensation circuit for outputting data line driving signals to data lines of the display panel according to the compensation signal and the data signal and for outputting scan line driving signals to the scan lines of the display panel according to the scan signal to drive the display panel to display images. 
         [0010]    The present invention further discloses a display control system of a display matrix. The display control system comprises an image control circuit for generating a data signal and a scan signal, a compensation circuit for generating a compensation signal according to a predetermined look-up table, and a driver circuit coupled to the image control circuit and the compensation circuit for outputting data line driving signals to data lines of the display matrix according to the compensation signal and the data signal and for outputting scan line driving signals to scan lines of the display matrix according to the scan signal to drive the display matrix to display images. 
         [0011]    The present invention also discloses a flat display. The flat display comprises a display panel for displaying images and a display control system. The display control system comprises an image control circuit coupled to the display panel for generating a data signal and a scan signal, a compensation circuit coupled to the image control circuit for generating a compensation signal according to a predetermined look-up table, and a driver circuit coupled to the image control circuit and the compensation circuit for outputting data line driving signals to data lines of the display panel according to the compensation signal and the data signal and for outputting scan line driving signals to scan lines of the display panel according to the scan signal to drive the display panel to display images. 
         [0012]    The present invention further discloses a method for compensating driving signals of a display panel. The method comprises generating a data signal and a scan signal; generating a compensation signal according to the distribution and magnitude of currents flowing through scan lines of the display panel; and outputting data line driving signals to data lines of the display panel according to the compensation signal and the data signal and outputting scan line driving signals to the scan lines of the display panel according to the scan signal. 
         [0013]    The present invention also discloses a method for compensating driving signals of a display panel. The method comprises generating a data signal and a scan signal; generating a compensation signal according to a predetermined look-up table; and outputting data line driving signals to data lines of the display panel according to the compensation signal and the data signal and outputting scan line driving signals to scan lines of the display panel according to the scan signal. 
         [0014]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is block diagram of a display control system according to the prior art. 
           [0016]      FIG. 2  is a schematic diagram of a display panel of the display control system shown in  FIG. 1 . 
           [0017]      FIG. 3  and  FIG. 4  respectively illustrate the relationship between the distance and the magnitude of the currents flowing through the scan lines shown in  FIG. 2 . 
           [0018]      FIG. 5  is a block diagram of a first embodiment display control system according to the present invention. 
           [0019]      FIG. 6  is a block diagram of a second embodiment display control system of the present invention. 
           [0020]      FIG. 7  illustrates the compensation for the reductions of currents shown in  FIG. 3 . 
           [0021]      FIG. 8  illustrates the compensation for the reductions of currents shown in  FIG. 4 . 
           [0022]      FIG. 9  is a timing diagram of data line driving signals according to the prior art. 
           [0023]      FIG. 10  is a timing diagram of data line driving signals according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    A display control system according to the present invention compensates data line driving signals to average the magnitude of currents. Please refer to  FIG. 5 , which is a block diagram of a display control system  2  according to the present invention. The display control system  2  comprises a display panel  10 , an image control circuit  12 , a driver circuit  24 , a compensation circuit  26 , and a current meter  28 . The current meter  28  is used to measure the distribution and the magnitude of the currents flowing through the scan lines of the display panel  10 . The image control circuit  12  sends a control signal to the compensation circuit  26  according to the distribution and the magnitude of the currents measured by the current meter  28 . The compensation circuit  26  generates a compensation signal according to the distribution of current flowing through the scan line of the display panel  10 . The driver circuit  24  receives data signals and scan signals from the image control circuit  12  and receives the compensation signal from the compensation circuit  26 , and then the driver circuit  24  generates a compensated data line driving signal to drive the scan lines according to the compensation signal and the data signals. Therefore, the data line driving signals according to the present invention are different from those of the prior art. 
         [0025]    Please refer to  FIG. 6 , which is a block diagram of a second embodiment display control system  3  of the present invention. The display control system  3  comprises a display panel  10 , an image control circuit  12 , a driver circuit  24 , a compensation circuit  26 , and a look-up table  30 . The image control system  3  provides compensation data to the image control circuit  12  according to the look-up table  30 . The image control circuit  12  transmits a control signal to the compensation circuit  26  to command the compensation circuit  26  to generate the compensation signal according to the compensation data. And then, the driver circuit  24  generates the compensated data line driving signal according to the compensation signal and the data signal. The look-up table  30  can be set up according to related data of the display panel  10 . 
         [0026]    The display control system of the present invention compensates the reductions of currents illustrated in  FIG. 3  and  FIG. 4 . Please refer to  FIG. 7  and  FIG. 8 .  FIG. 7  illustrates the compensation for the reductions of currents shown in  FIG. 3 , and  FIG. 8  illustrates the compensation for the reductions of currents shown in  FIG. 4 . By using the compensation for each data line  0 - n  shown in  FIG. 7  and  FIG. 8 , the brightness of each scan lines  11  and  13  can be balanced. Please refer to  FIG. 9  and  FIG. 10 .  FIG. 9  is a timing diagram of data line driving signals according to the prior art, and  FIG. 10  is a timing diagram of data line driving signals according to the present invention. As shown in  FIG. 9 , the time intervals t 1  of the data line driving signals for driving the data lines are the same. In contrast with the prior art, the time intervals of the data line driving signals for driving the data lines according to the present invention are different. In the condition that order numbers of the data lines are ascending from the left to the right and the initial ends of the scan lines  13  are adjacent to the data line n, the time intervals of the data line driving signals for driving the data lines  0 - m  are extended t 2  (as shown in  FIG. 10 ) to compensate the brightness near the final ends of the scan lines  13 , where 0≦m&lt;n. By extending the length of the time intervals for driving the data lines, the durations when the corresponding light emitting elements emit light are properly prolonged to uniform the brightness of the display panel. In addition, a pulse width modulation (PWM) technique can be used to extend the length of the time intervals for driving the data lines. 
         [0027]    Moreover, the display panel of the present invention can be an OLED panel or other flat display panel consisting of a matrix of specific current-driven elements. The way for arranging the scan lines of the display panel of the present invention is not limited to what is shown in  FIG. 2 . The present invention can be applied to any kind of arrangement of the scan lines. 
         [0028]    In contrast with the prior art, the present invention disclosed a display control system and a related method for compensating driving signals of a display panel. The brightness of the panel is made uniform by extending the length of the time intervals for driving the data lines. The extensions of the length of the time intervals for driving the data lines are determined according to a compensation signal provided by a compensation circuit. Therefore, the problem in which the display panel has unbalanced brightness or has lower brightness on left side or right side can be solved. 
         [0029]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.