Patent Publication Number: US-2018040286-A1

Title: Display driver circuit board, driving method thereof, and display device

Description:
RELATED APPLICATIONS 
     This application claims priority to Chinese Patent Application No. 201710381087.5, filed May 25, 2017, the content of which is hereby incorporated by reference in its entirety. 
     FIELD 
     The present disclosure relates to the field of display technologies, and particularly to a display driver circuit board, a driving method thereof, and a display device. 
     BACKGROUND 
     At present, a liquid crystal display panel as illustrated in  FIG. 1  comprises a display panel, a display driver circuit board PCB connected with the display pane Panel, and a plurality of source driver chips IC 1 , IC 2 , IC 3 , and IC 4  bound on an edge frame of the display panel by a Chip On Film (COF), where the display driver circuit board PCB includes a timing control circuit (Tcon) and a power source management circuit (DC-DC); the timing control circuit is configured to output a frame start signal (STV) A to the respective source driver chips IC 1 , IC 2 , IC 3 , and IC 4  at a preset display refresh frequency; and the power source management circuit is configured to output fixed common voltage B to the respective source driver chips IC 1 , IC 2 , IC 3 , and IC 4  after determining the optimum common voltage (Vcom) according to a characteristic of the display panel. 
     As liquid crystal display panels with high definition (UHD and WQ+) and a large size ( 12 ′ to  40 ′) are being developed constantly, power consumption of the liquid crystal display panels are also being increased, so there are a number of power consumption lowering methods emerging. For example, static pictures can be displayed by lowering the display refresh frequency from 60 Hz as illustrated in  FIG. 2A  to 45 Hz as illustrated in  FIG. 2B , and inserting a media stream storage frame between two frames of pictures to thereby lower power consumption. However the uniformity of the characteristic of the display pane Panel may be less stabilized, and a factor of flicker may be degraded by 5 dB to 10 dB due to the lower display refresh frequency, thus significantly degrading the display quality of the display panel in a low power-consumption application. 
     In view of this, it is highly desirable to address the problem of a degraded factor of flicker in the display panel being used when frequency is changed. 
     SUMMARY 
     Embodiments of the disclosure provide a display driver circuit board, a driving method thereof, and a display device so as to address the problem of a degraded factor of flicker in the display panel being used when frequency is changed in the related art. 
     In an aspect, an embodiment of the disclosure provides a display driver circuit board including: a timing control circuit, a power source management circuit, a display refresh frequency detection unit, and a common voltage pre-storage and compensation unit, wherein the timing control circuit is configured to output a frame start signal at a preset display refresh frequency, the display refresh frequency detection unit is electrically connected with the timing control circuit and the common voltage pre-storage and compensation unit, and configured to detect the display refresh frequency of the frame start signal output by the timing control circuit, and to output the detected display refresh frequency to the common voltage pre-storage and compensation unit; and the common voltage pre-storage and compensation unit is electrically connected with the power source management circuit, and configured to determine common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to a pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and to control the power source management circuit to output the common voltage corresponding to the display refresh frequency. 
     In another aspect, an embodiment of the disclosure further provides a display device including a display panel, and the display driver circuit board according to the embodiment of the disclosure, connected with the display panel. 
     In another aspect, an embodiment of the disclosure further provides a method for driving a display driver circuit board, the method including 
     outputting, by a timing control circuit, a frame start signal at a preset display refresh frequency, and detecting, by a display refresh frequency detection unit, the display refresh frequency of the frame start signal output by the timing control circuit, and outputting the detected display refresh frequency to a common voltage pre-storage and compensation unit; and determining, by the common voltage pre-storage and compensation unit, a common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to a pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and controlling the power source management circuit to output the common voltage corresponding to the display refresh frequency. 
     Certain advantageous effects of the disclosure may be as follows: 
     In the display driver circuit board, the driving method of the same, and the display device according to the embodiments of the disclosure, the display refresh frequency detection unit and the common voltage pre-storage and compensation unit are added to the display driver circuit board, so that the display refresh frequency detection unit can detect the display refresh frequency of the frame start signal output by the timing control circuit, and output the detected display refresh frequency to the common voltage pre-storage and compensation unit, and thereafter the common voltage pre-storage and compensation unit can determine the common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to the pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and control the power source management circuit to output the common voltage corresponding to the display refresh frequency, so that the display driver circuit board can adjust in real time the output common voltage according to the varying display refresh frequency to thereby guarantee the output common voltage to be the optimum common voltage matching the display refresh frequency, thus facilitating an improvement in stabilized uniformity of the display panel, and addressing a factor of flicker so as to improve the display quality of the display panel, and improve user experience. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic structural diagram of a display panel in the related art; 
         FIG. 2A  is a schematic diagram of displaying at a display refresh frequency of 60 Hz in the related art; 
         FIG. 2B  is a schematic diagram of displaying at a lower display refresh frequency of 45 Hz in the related art; 
         FIG. 3  is a schematic structural diagram of a display driver circuit board according to an embodiment of the disclosure; 
         FIG. 4A  to  FIG. 4D  are four other schematic structural diagrams of a display driver circuit board according to embodiments of the disclosure; 
         FIG. 5A  to  FIG. 5C  are three other schematic structural diagrams of a display driver circuit board according to embodiments of the disclosure; 
         FIG. 6  is a schematic circuit structural diagram of a display driver circuit board according to an embodiment of the disclosure; 
         FIG. 7  is a flow chart of a driving method of a display driver circuit board according to an embodiment of the disclosure; 
         FIG. 8  is a schematic structural diagram of a display device according to an embodiment of the disclosure; 
         FIG. 9  is a schematic structural diagram of a display device according to an embodiment of the disclosure in a side view; and 
         FIG. 10  is a schematic diagram of a product of a display device according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A display driver circuit board, a driving method thereof, and a display device according to embodiments of the disclosure will be described below in details with reference to the drawings. 
     As illustrated in  FIG. 3 , a display driver circuit board according to an embodiment of the disclosure can include a timing control circuit  100 , a power source management circuit  200 , a display refresh frequency detection unit  300 , and a common voltage pre-storage and compensation unit  400 , where: 
     The timing control circuit  100  is configured to output a frame start signal (STV) A at a preset display refresh frequency; 
     The display refresh frequency detection unit  300  is electrically connected with the timing control circuit  100  and the common voltage pre-storage and compensation unit  400 , and configured to detect the display refresh frequency of the frame start signal A output by the timing control circuit  100 , and to output the detected display refresh frequency to the common voltage pre-storage and compensation unit  400 ; and 
     The common voltage pre-storage and compensation unit  400  is electrically connected with the power source management circuit  200 , and configured to determine common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit  300  according to a pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and to control the power source management circuit  200  to output the common voltage (Vcom) B corresponding to the display refresh frequency. 
     In the display driver circuit board above according to the embodiment of the disclosure, the display refresh frequency detection unit  300  and the common voltage pre-storage and compensation unit  400  are added to the display driver circuit board in the related art. The additional display refresh frequency detection unit  300  can detect the display refresh frequency of the frame start signal A output by the timing control circuit  100 , and output the detected display refresh frequency to the common voltage pre-storage and compensation unit  400 , and thereafter the additional common voltage pre-storage and compensation unit  400  can determine the common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit  300  according to the pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and control the power source management circuit  200  to output the common voltage (Vcom) B corresponding to the display refresh frequency, so that the display driver circuit board can adjust in real time the output common voltage B according to the varying display refresh frequency to thereby guarantee the output common voltage B to be the optimum common voltage matching the display refresh frequency, thus facilitating an improvement in stabilized uniformity of the display panel, and addressing a factor of flicker so as to improve the display quality of the display panel, and improve user experience. 
     In an implementation, in the display driver circuit board above according to the embodiment of the disclosure, in order to guarantee the reliability and stability of the respective elements in the display driver circuit board, the additional display refresh frequency detection unit  300  and common voltage pre-storage and compensation unit  400  can be separate from the original elements in the display driver circuit board, that is, the timing control circuit  100 , the power source management circuit  200 , the display refresh frequency detection unit  300 , and the common voltage pre-storage and compensation unit  400  can be separate from each other in the display driver circuit board as illustrated in  FIG. 3 . 
     Alternatively in an implementation, in the display driver circuit board above according to the embodiment of the disclosure, in order to guarantee the integrity of the respective elements in the display driver circuit board, one of the additional display refresh frequency detection unit  300  and common voltage pre-storage and compensation unit  400  can be integrated in one of the original elements in the display driver circuit board. 
     In an implementation, in the display driver circuit board above according to the embodiment of the disclosure, as illustrated in  FIG. 4A , for example, the display refresh frequency detection unit  300  can be integrated in the timing control circuit  100  so that the timing control circuit  100  outputs the display refresh frequency directly to the common voltage pre-storage and compensation unit  400  while outputting the frame start signal A; or as illustrated in  FIG. 4B , the display refresh frequency detection unit  300  can be integrated in the power source management circuit  200 , although the embodiment of the disclosure will not be limited thereto. 
     In an implementation, in the display driver circuit board above according to the embodiment of the disclosure, as illustrated in  FIG. 4C , the common voltage pre-storage and compensation unit  400  can be integrated in the power source management circuit  200  so that the power source management circuit  200  can output the corresponding common voltage directly upon reception of the display refresh frequency output by the display refresh frequency detection unit  300 ; or as illustrated in  FIG. 4D , the common voltage pre-storage and compensation unit  400  can be integrated in the timing control circuit  100 , although the embodiment of the disclosure will not be limited thereto. 
     Furthermore in an implementation, in the display driver circuit board above according to the embodiment of the disclosure, in order to guarantee the integrity of the respective elements in the display driver circuit board, both the additional display refresh frequency detection unit  300  and common voltage pre-storage and compensation unit  400  can be integrated in one of the original elements in the display driver circuit board. 
     In an implementation, in the display driver circuit board above according to the embodiment of the disclosure, as illustrated in  FIG. 5A , for example, the display refresh frequency detection unit  300  can be integrated in the timing control circuit  100 , and also the common voltage pre-storage and compensation unit  400  can be integrated in the power source management circuit  200 , so that the timing control circuit  100  outputs the display refresh frequency directly to the power source management circuit  200  while outputting the frame start signal A, and the power source management circuit  200  can output the corresponding common voltage directly upon reception of the display refresh frequency; or as illustrated in  FIG. 5B , both the display refresh frequency detection unit  300  and the common voltage pre-storage and compensation unit  400  can be integrated in the timing control circuit  100  so that the timing control circuit  100  controls the power source management circuit  200  directly to output the corresponding common voltage while outputting the frame start signal A; or as illustrated in  FIG. 5C , both the display refresh frequency detection unit  300  and the common voltage pre-storage and compensation unit  400  can be integrated in the power source management circuit  200  so that the power source management circuit  200  outputs the corresponding common voltage directly upon detection of the display refresh frequency of the frame start signal A, although the embodiment of the disclosure will not be limited thereto. 
     In an implementation, in the display driver circuit board above according to the embodiment of the disclosure, the correspondence relationship between respective display refresh frequencies and respective common voltages pre-stored in the common voltage pre-storage and compensation unit  400  is a predetermined correspondence relationship between a plurality of possible display refresh frequencies of the frame start signal A, and their corresponding optimum common voltages, where the optimum common voltage refers to such common voltage at the display refresh frequency that enable the driven display plane to flicker the least. For example, the start frame signal A output by the timing control circuit  100  may be output at four display refresh frequencies of 70 Hz, 60 Hz, 50 Hz, and 40 Hz. At this time, listed common voltages corresponding to these display refresh frequencies respectively are as depicted in Table 1 below. As can be apparent, typically the common voltage is lower at a higher display refresh frequency. 
     
       
         
           
               
               
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                 Frequency (Hz) 
                 70 
                 — 
                 60 
                 — 
                 50 
                 — 
                 40 
               
               
                 Common voltage (V) 
                 3 
                 — 
                 3.3 
                 — 
                 3.5 
                 — 
                 3.8 
               
               
                   
               
            
           
         
       
     
     In an implementation, in the display driver circuit board above according to the embodiment of the disclosure, as illustrated in  FIG. 6 , the display refresh frequency detection unit  300  can be embodied as a monolithic processor MCU to perform the functions thereof, and the common voltage pre-storage and compensation unit  400  can be embodied as an Electrically Erasable Programmable Read Only Memory (EEPROM) to perform the functions thereof. 
     Based upon the same inventive idea, an embodiment of the disclosure further provides a driving method of a display driver circuit board, and since the method addresses the problem under a similar principle to the display driver circuit board above, reference can be made to the implementation of the display driver circuit board above for an implementation of the method, so a repeated description thereof will be omitted here. 
     An embodiment of the disclosure provides a driving method of a display driver circuit board as illustrated in  FIG. 7 , where the method includes the following steps: 
     In the step S 701 , a timing control circuit outputs a frame start signal at a preset display refresh frequency, and a display refresh frequency detection unit detects the display refresh frequency of the frame start signal output by the timing control circuit, and outputs the detected display refresh frequency to a common voltage pre-storage and compensation unit; and 
     In the step S 702 , the common voltage pre-storage and compensation unit determines common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to a pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and controls the power source management circuit to output the common voltage corresponding to the display refresh frequency. 
     In the driving method above of a display driver circuit board according to the embodiment of the disclosure, the display refresh frequency detection unit can detect the display refresh frequency of the frame start signal output by the timing control circuit, and output the detected display refresh frequency to the common voltage pre-storage and compensation unit, and thereafter the common voltage pre-storage and compensation unit can determine the common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to the pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and control the power source management circuit to output the common voltage corresponding to the display refresh frequency, so that the display driver circuit board can adjust in real time the output common voltage according to the varying display refresh frequency to thereby guarantee the output common voltage to be the optimum common voltage matching the display refresh frequency, thus facilitating an improvement in stabilized uniformity of the display panel, and addressing a factor of flicker so as to improve the display quality of the display panel, and improve user experience. 
     Based upon the same inventive idea, an embodiment of the disclosure further provides a display device as illustrated in  FIG. 8  and  FIG. 9 , which includes a display panel, and the display driver circuit board PCB according to any one of the embodiments above of the disclosure, connected with the display panel. The display device can be a mobile phone as illustrated in  FIG. 10 , a tablet computer, a TV set, a display, a notebook computer, a digital photo frame, a navigator, and any other product or component capable of displaying. Reference can be made to the embodiments of the display driver circuit board above for an implementation of the display device, so a repeated description thereof will be omitted here. 
     In the display device above according to the embodiment of the disclosure, the display refresh frequency detection unit and the common voltage pre-storage and compensation unit are added to the display driver circuit board, so that the display refresh frequency detection unit can detect the display refresh frequency of the frame start signal output by the timing control circuit, and output the detected display refresh frequency to the common voltage pre-storage and compensation unit, and thereafter the common voltage pre-storage and compensation unit can determine the common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to the pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and control the power source management circuit to output the common voltage corresponding to the display refresh frequency, so that the display driver circuit board can adjust in real time the output common voltage according to the varying display refresh frequency to thereby guarantee the output common voltage to be the optimum common voltage matching the display refresh frequency, thus facilitating an improvement in stabilized uniformity of the display panel, and addressing a factor of flicker so as to improve the display quality of the display panel, and improve user experience. 
     In the display device above according to the embodiment of the disclosure, the display panel can be a liquid crystal display panel, an organic electroluminescent display panel, a plasma display panel, etc. The display panel may be a rigid display panel or may be a flexible display panel, although the embodiment of the disclosure will not be limited thereto. 
     In the display device above according to the embodiment of the disclosure, if the display panel is a liquid crystal display panel, then the liquid crystal display panel may generally include an array substrate and a color filter substrate arranged opposite to each other, and as illustrated in  FIG. 8  and  FIG. 9 , the liquid crystal display panel may further include a plurality of source driver chips IC 1 , IC 2 , IC 3 , and IC 4  bound on an edge frame of the display panel by a Chip On Film (COF). The respective source driver chips IC 1 , IC 2 , IC 3 , and IC 4  are typically bound on an edge frame of the array substrate of the display panel by a Chip On Film (COF). The source driver chips IC 1 , IC 2 , IC 3 , and IC 4  are configured to receive the frame start signal output by the timing control circuit  100  in the display driver circuit board PCB at the preset display refresh frequency, and to receive the common voltage, corresponding to the display refresh frequency, output by the power source management circuit  200 . 
     In the display driver circuit board, the driving method of the same, and the display device according to the embodiments of the disclosure, the display refresh frequency detection unit and the common voltage pre-storage and compensation unit are added to the display driver circuit board, so that the display refresh frequency detection unit can detect the display refresh frequency of the frame start signal output by the timing control circuit, and output the detected display refresh frequency to the common voltage pre-storage and compensation unit, and thereafter the common voltage pre-storage and compensation unit can determine the common voltage corresponding to the display refresh frequency output by the display refresh frequency detection unit according to the pre-stored correspondence relationship between respective display refresh frequencies and respective common voltages, and control the power source management circuit to output the common voltage corresponding to the display refresh frequency, so that the display driver circuit board can adjust in real time the output common voltage according to the varying display refresh frequency to thereby guarantee the output common voltage to be the optimum common voltage matching the display refresh frequency, thus facilitating an improvement in stabilized uniformity of the display panel, and addressing a factor of flicker so as to improve the display quality of the display panel, and improve user experience. 
     Evidently those skilled in the art can make various modifications and variations to the disclosure without departing from the spirit and scope of the disclosure. Accordingly the disclosure is also intended to encompass these modifications and variations thereto so long as the modifications and variations come into the scope of the claims appended to the disclosure and their equivalents.