Patent Publication Number: US-2023155586-A1

Title: Driving device and driving method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Taiwan Application Serial Number 110143052, filed Nov. 18, 2021, which is herein incorporated by reference in its entirety. 
     BACKGROUND 
     Field of Invention 
     The present disclosure relates to a display device and a display method. More particularly, the present disclosure relates to a driving device and a driving method applied to a light-emitting diode display. 
     Description of Related Art 
     At present, the signal transmission of LED driver IC mostly uses the single-ended signal or the differential signal, but the transmission speed of the single-ended signal is limited. However, in order to use the differential signal transmission, the number of signal lines needs to be doubled. 
     SUMMARY 
     The present disclosure provides a driving device. The driving device comprises a first complementary metal-oxygen-semiconductor circuit and a first comparator. The first complementary metal-oxygen-semiconductor circuit is configured to output a power signal or a pull-down signal according to a first input signal. The first comparator comprises a first non-inverting input terminal and a first inverting input terminal. The first non-inverting input terminal is coupled to the first complementary metal-oxygen-semiconductor circuit, and is configured to receive the power signal or the pull-down signal. The first inverting input terminal is configured to receive a first reference signal, wherein the first comparator is configured to compare one of the power signal and the pull-down signal and the first reference signal to provide a first driving signal. 
     The present disclosure provides a driving method. The driving method comprises: outputting a power signal or a pull-down signal according to a first input signal by a first complementary metal-oxygen-semiconductor circuit; receiving the power signal or the pull-down signal by a first non-inverting input terminal of a first comparator; receiving a first reference signal by a first inverting input terminal of the first comparator; and comparing one of the power signal and the pull-down signal and the first reference signal to provide a first driving signal by the first comparator. 
     Therefore, according to the technical content of the present disclosure, the driving device and the driving method of the present disclosure can be applied to a light-emitting diode display with high display quality. In addition, the use of the driving device and the driving method of the present disclosure improve the signal transmission speed without doubling the number of signal lines, so the problem of affecting the display signal transmission speed can be improved. 
     It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG.  1    is a schematic diagram of a driving device according to one embodiment of the present disclosure. 
         FIG.  2    is a schematic diagram of a waveform of a driving signal level according to one embodiment of the present disclosure. 
         FIG.  3    is a schematic diagram of a display system according to one embodiment of the present disclosure. 
         FIG.  4    is a detailed circuit diagram of a driving device according to one embodiment of the present disclosure. 
         FIG.  5    is a detailed circuit diagram of a driving device according to one embodiment of the present disclosure. 
         FIG.  6    is a schematic diagram of waveforms of a plurality of control signal levels according to one embodiment of the present disclosure. 
         FIG.  7    shows a flowchart of a driving method according to an alternative implementation of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
       FIG.  1    is a schematic diagram of a driving device according to one embodiment of the present disclosure. As shown in the figure, the driving device  100  includes a first complementary metal-oxygen-semiconductor circuit  110  and a first comparator  120 . The first comparator  120  includes a first non-inverting input terminal  121  and a first inverting input terminal  123 . In connection relationship, the first non-inverting input terminal  121  is coupled to the first complementary metal-oxygen-semiconductor circuit  110 . 
     In order to provide a driving device technology that increases the signal transmission speed without doubling the number of signal lines, the present disclosure provides the driving device  100  as shown in  FIG.  1   , and the related operations are described in detail as below. 
     In one embodiment, the first complementary metal-oxygen-semiconductor circuit  110  is configured to output a power signal VDD or a pull-down signal VSS according to a first input signal. 
     Then, the first non-inverting input terminal  121  is configured to receive the power signal VDD or the pull-down signal VSS. Subsequently, the first inverting input terminal  123  is configured to receive a first reference signal VREF_ 1 . 
     Next, the first comparator  120  is configured to compare one of the power signal VDD and the pull-down signal VSS and the first reference signal VREF_ 1  to provide a first driving signal. For example, the first comparator  120  can receive the differential signal and the single-ended signal, but the present disclosure is not limited to this embodiment. 
       FIG.  2    is a schematic diagram of a waveform of a driving signal level according to one embodiment of the present disclosure. Please refer to  FIG.  1    and  FIG.  2    together, in one embodiment, a reference voltage value VREF of the first reference signal VREF_ 1  is between the power signal VDD and the pull-down signal VSS. For example, the reference voltage value VREF of the first reference signal VREF_ 1  can be W×(VDD−VSS), and W is less than 1. For example, W can be 0.4˜0.6, but the present disclosure is not limited to this embodiment. 
     In one embodiment, the driving voltage value of the first driving signal is between a high threshold VIH and the power signal VDD, wherein the high threshold includes a sum of the first reference signal and a parameter A, and the parameter A is a positive number greater than 0. For example, the first reference signal VREF_ 1  can be a reference signal VREF, the driving voltage value of the first driving signal can be a high-level voltage, and the high threshold VIH can be VREF+A (e.g., the reference signal VREF+a parameter A), and the parameter A is a positive number greater than 0. When the driving voltage value of the first driving signal is between the high threshold VIH and the power signal VDD, the first driving signal is the high-level voltage. 
     In one embodiment, the driving voltage value of the first driving signal is between a low threshold VIL and the pull-down signal VSS, wherein the low threshold includes a difference between the first reference signal and the parameter A, and the parameter A is a positive number greater than 0. For example, the first reference signal VREF_ 1  can be the reference signal VREF, the driving voltage value of the first driving signal can be a low-level voltage, and the low threshold VIL can be VREF−A (e.g., the reference signal VREF− the parameter A), and the parameter A is a positive number greater than 0. When the driving voltage value of the first driving signal is between the low threshold VIL and the pull-down signal VSS, the first driving signal is the low-level voltage. 
     In one embodiment, a difference between the high-level voltage and the low-level voltage is a swing value, and the swing value is related to the signal transmission speed. For example, if the high-level voltage is VREF_ 1 +A+1 and the low-level voltage is VREF_ 1 −A−1, the swing value is (VREF_ 1 +A+1)−(VREF_ 1 −A− 1 )= 2 A+2, and the swing value is bigger than  2 A. When the swing value decreases, the rise time (TR) and the fall time (TF) can be shortened, thereby increasing the signal transmission speed. 
       FIG.  3    is a schematic diagram of a display system according to one embodiment of the present disclosure.  FIG.  4    is a detailed circuit diagram of a driving device according to one embodiment of the present disclosure. 
     Please refer to  FIG.  3   , the display system  200  includes a first driver  210 , a second driver, a Nth driver  290 , a controller  800 , and a panel  900 . In connection relationship, the first driver  210  is coupled to the controller  800 , the second driver  230  is coupled to the first driver  210 , and the panel  900  is coupled to the first driver  210 , the second driver  230 , and the Nth driver  290 . 
     In operation, in one embodiment, the first driver  210  receives the data signal DATA, the timing sequence signal CL, and the reference signal VREF. For example, the reference signal VREF can be the first reference signal VREF_ 1 , the data signal DATA can be data signal DATA_IN, and the timing sequence signal CLK can be timing sequence signal CLK_IN. 
     Then, the first driver  210  transmits the data signal DATA, the timing sequence signal CLK, and the reference signal VREF to the second driver  230 . For example, the data signal DATA can be data signal DATA_OUT, the timing sequence signal CLK can be the timing sequence signal CLK_OUT, and the reference signal VREF can be first reference signal VREF_ 1 . 
     Subsequently, the first driver  210  combines the above-mentioned data signal DATA, the timing sequence signal CLK, and the reference signal VREF to form the image data, and the image data is converted into the driving signals to be coupled to the pixels in the panel  900 . For example, the driving signals can be the signals OUT_R, OUT_G, OUT_B, etc. which are coupled to the pixels in the panel  900 . 
     Next, the operation mode of the second driver  230  is similar to that of the first driver  210 , so it is not repeated here. 
     Please refer to  FIG.  1   ,  FIG.  3   , and  FIG.  4   , in one embodiment, the driving device  300  of  FIG.  4    further includes a beginning comparator  211  and a first logic circuit  213  compared to the driving device  100  of  FIG.  1   , and the beginning comparator  211  includes a beginning non-inverting input terminal  2111  and a beginning inverting input terminal  2113 . In connection relationship, the first logic circuit  213  is coupled to the beginning comparator  211 , and the first logic circuit  213  is coupled to the first complementary metal-oxygen-semiconductor circuit  110 . 
     In one embodiment, in operation, the beginning non-inverting input terminal  2111  is configured to receive the beginning signal. 
     Then, the beginning inverting input terminal  2113  is configured to receive the beginning reference signal VREF_ 0 . 
     Subsequently, the first logic circuit  213  is configured to receive the beginning driving signal and provide the first input signal according to the beginning driving signal. 
     Please refer to  FIG.  4   , in one embodiment, the driving device  300  of  FIG.  4    further includes a second logic circuit  215  and a second complementary metal-oxygen-semiconductor circuit  217  compared to the driving device  100  of  FIG.  1   . In connection relationship, the second logic circuit  215  is coupled to the first comparator  120 , and the second complementary metal-oxygen-semiconductor circuit  217  is coupled to the second logic circuit  215 . 
     In one embodiment, in operation, the second logic circuit  215  is configured to receive the first driving signal and provide the second input signal according to the first driving signal. 
     Then, the second complementary metal-oxygen-semiconductor circuit  217  is configured to provide the power signal VDD or the pull-down signal VSS according to the second input signal. 
     In one embodiment, the driving device  300  of  FIG.  4    includes the beginning comparator  211 , the first logic circuit  213 , the first complementary metal-oxygen-semiconductor circuit  110 , the first comparator  120 , the second logic circuit  215 , and the second complementary metal-oxygen-semiconductor circuit  217 . The connection relationship and the operation are similar to those described in  FIG.  4    above, and thus are not repeated here. 
     In one embodiment, each of the beginning comparator  211 , the first logic circuit  213 , the first complementary metal-oxygen-semiconductor circuit  110 , the first comparator  120 , the second logic circuit  215 , and the second complementary metal-oxygen-semiconductor circuit  217  of the driving device  300  in  FIG.  4    is plural. For example, the number of the plural of the elements as mentioned above can be 2 or 3, but the present disclosure is not limited to this embodiment. 
     In one embodiment, the beginning signal includes at least one of the data signal DATA and the timing sequence signal CLK. 
     In one embodiment, the beginning comparator  211  continues to receive the beginning reference signal VREF_ 0 , the first comparator  120  continues to receive the first reference signal VREF_ 1 , the beginning reference signal VREF_ 0  includes the reference voltage value VREF, and the first reference signal VREF_ 1  includes the reference voltage value VREF. For example, the beginning comparator  211  continues to receive the reference voltage value VREF, and the first comparator  120  continues to receive the reference voltage value VREF. 
       FIG.  5    is a detailed circuit diagram of the driving device according to one embodiment of the present disclosure. Please refer to  FIG.  4    and  FIG.  5   , the driving device  300  of  FIG.  5    further includes a Nth comparator  291  compared to the driving device  300  of  FIG.  4   , the Nth comparator  291  includes a Nth non-inverting input terminal  2911  and a Nth inverting input terminal  2913 , and N is a positive integer greater than 1. In addition, the connection relationship and the operation of the Nth comparator  291  are similar to those of the first comparator  120 , and thus will not be repeated here. 
     In one embodiment, each of the beginning comparator  211 , the first logic circuit  213 , the first complementary metal-oxygen-semiconductor circuit  110 , the first comparator  120 , the second logic circuit  215 , the second complementary metal-oxygen-semiconductor circuit  217 , and the Nth comparator  291  of the driving device  300  in  FIG.  5    is plural. For example, the number of the plural of the elements as mentioned above can be 2 or 3, but the present disclosure is not limited to this embodiment. 
       FIG.  6    is a schematic diagram of waveforms of a plurality of control signal levels according to one embodiment of the present disclosure. Please refer to  FIG.  5    and  FIG.  6   , in one embodiment, at the first moment T 1 , the beginning inverting input terminal  2113  receives the beginning reference signal VREF_ 0 . For example, before the first moment T 1 , the beginning inverting input terminal  2113  receives the pull-down signal VSS, and at the first moment T 1 , the beginning inverting input terminal  2113  receives the beginning reference signal VREF_ 0 . In addition, the pull-down signal VSS can be grounded, that means there is no signal. 
     In one embodiment, at the second moment T 2 , the first inverting input terminal  123  receives the first reference signal VREF_ 1 . For example, before the second moment T 2 , the first inverting input terminal  123  receives the pull-down signal VSS, and at the second moment T 2 , the first inverting input terminal  123  receives the first reference signal VREF_ 1 . In addition, the pull-down signal VSS can be grounded, that means there is no signal. 
     In one embodiment, at the third moment T 3 , the second inverting input terminal (for example: the inverting input terminal  2913 ) receives the second reference signal VREF_ 2 . For example, before the third moment T 3 , the second inverting input terminal (for example: the inverting input terminal  2913 ) receives the pull-down signal VSS, and at the third moment T 3 , the second inverting input terminal (for example: the inverting input terminal  2913 ) receives the second reference signal VREF_ 2 . In addition, the pull-down signal VSS can be grounded, that means there is no signal. 
       FIG.  7    shows a flowchart of a driving method according to an alternative implementation of the present disclosure. In order to make the driving method  700  of  FIG.  7    easier to understand, please refer to  FIGS.  1  and  7    together. The driving method  700  of  FIG.  7    includes the following steps: 
     Step  710 : outputting a power signal or a pull-down signal according to a first input signal by a first complementary metal-oxygen-semiconductor circuit  110 ; 
     Step  720 : receiving the power signal or the pull-down signal by a first non-inverting input terminal  121  of a first comparator  120 ; 
     Step  730 : receiving a first reference signal by a first inverting input terminal  123  of the first comparator  120 ; 
     Step  740 : comparing one of the power signal and the pull-down signal and the first reference signal to provide a first driving signal by the first comparator  120 . 
     It can be seen from the above embodiments of the present disclosure that the application of the present disclosure has the following advantages. The driving device and the driving method shown in the embodiment of the present disclosure can be applied to a light-emitting diode display with high display quality. In addition, the use of the driving device of the present disclosure improves the signal transmission speed without doubling the number of signal lines, so the problem of the display signal transmission speed can be improved. 
     Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention 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.