Abstract:
The present invention proposes a gate driver including a plurality of gate driver on array (GOA) units. Each of the GOA unit includes a main driving circuit, a starting signal output circuit, and a plurality of gate driving circuits. The gate driver utilizes a starting signal and two inversed clock signals to control the charging period and the discharging period of the gate driver. Furthermore, the gate driver utilizes multiple clock signals to control the output of the gate driving signals. In this way, the number of the clock signals is reduced and thus the power consumption is also reduced.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a gate driver of a liquid crystal display (LCD), and more particularly to a gate driver on array (GOA) circuit and an LCD. 
       BACKGROUND OF THE INVENTION 
       [0002]    Gate driver on array (GOA) techniques have been widely used in LCD design. This structure not only saves the expenses of the gate driver chips, but also reduces the width of side frame of the LCD to allow a narrow side frame structure. 
         [0003]    As the size and the resolution of the LCD increase, the clock signals (CK) for the GOA circuits become various. In general, a high definition (HD) panel (e.g., the resolution is 1280*720) uses 4 clock signals in the GOA circuits. Furthermore, a full high definition (FHD) panel utilizes 6 or 8 clock signals. The clock signal is a high-frequency signal in which a high voltage level and a low voltage level switch frequently. However, the power consumption of the gate driver is related to the power consumptions of transistors caused by crossing currents passing through the transistors. In addition, the power consumption of the transistors is proportional to the squared switching frequency of the clock signal. Therefore, if the number of the clock signal is larger or the frequency of the clock signal is higher, the power consumption of the gate driver is significant. 
         [0004]    Please refer to  FIG. 1 . The GOA circuit  100  comprises 4 transistors and 1 capacitor. The GOA circuit of current stage outputs a gate driving signal G(n) and provides an intermediate signal, which is a starting signal ST(n), to a GOA circuit of next stage. The GOA circuit  100  comprises a main driving circuit  120  and an output circuit  150 . The main driving circuit  120  comprises a transistor T 1  and a transistor T 2 . The transistor T 1  is turned on in response to a starting signal ST (n−2). The transistor T 2  is turned on to transmit the voltage source Vss to reset the signal Q(n) in response to a gate driving signal G(n+2) being received. 
         [0005]    The output circuit  150  comprises a transistor T 3 , a transistor T 4 , and a transistor T 8 . The transistor T 4  is turned on in response to signal Q(n). When the transistor T 4  is turned on, the clock signal CK is transferred to the source and thus the gate driving signal G(n) is outputted. In addition, the transistor T 8  is turned on in response to a gate driving signal G(n+2) and thus the voltage source Vss is transferred through the transistor T 8  to reset the gate driving signal G(n). 
         [0006]    Because of the reliability of amorphous silicon, a pull-down circuit  15  needs to be additionally provided. The pull-down circuit  15  is used to ensure the voltage levels of the node Q and the output node of the GOA circuit when the GOA circuit is in a deactivation state. In other words, the pull-down circuit  15  is able to pull down the voltage levels of the node Q and the output node and thus raise the reliability of the GOA circuit  100 . 
         [0007]    GOA circuit of a large-size high-definition display often adopts multiple clock signals, such as 6 or 8 clock signals, to ensure the reliability. Please refer to  FIG. 2 , which is a diagram of a conventional two-stage GOA circuit driven by  6  different phases. In  FIG. 2 , the first stage  210  of the GOA circuit generates three gate driving signals G(N), G(N+1), and G(N+2) in response to two gate driving signals G(N-1) and G(N+5) and six input clock signals CK 1 , CK 2 , CK 3 , XCK 1 , XCK 2 , and XCK 3 . 
         [0008]    Please refer to  FIG. 3 , which is a timing diagram corresponding to operations of the GOA circuit. As shown in  FIG. 3 , the accumulated width of the gate driving signals G(N)−G(N+5) and the clock signals CK 1 -CK 3  and XCK 1 −XCK 3  is 3W. W is a time period of charging a single scan line. The power is mainly consumed due to the clock signals. In general, the power consumption is proportional to the voltage of the clock signals squared. Therefore, if the number of the clock signals is larger, the power consumption is more significant. This problem becomes more severe when the resolution of the display is higher. Furthermore, the large number of the clock signals also increases the cost of the driving circuit and thus reduces its competitiveness. 
         [0009]    Therefore, a new structure of GOA is required to solve the above-mentioned problem of a large number of clock signals and huge power consumption. This new structure may reduce the number of clock signals and reduce the power consumption of the GOA circuit to meet the demands of green products. 
       SUMMARY OF THE INVENTION 
       [0010]    One objective of exemplary embodiments of the present disclosure is to provide a gate driver. The gate driver utilizes an intermediate signal (starting signal) and two inversed clock signals to control the charging period and the discharging period of the gate driver. Furthermore, the gate driver utilizes multiple clock signals to control the output of the gate driving signals. In this way, the number of the clock signals is reduced and thus the power consumption is also reduced. 
         [0011]    One objective of the exemplary embodiments is to provide a gate driver. The gate driver utilizes an intermediate signal (starting signal) and two inversed clock signals to control the voltage level of the node Q. Furthermore, the gate driver utilizes multiple clock signals to control the output of the gate driving signals. In this way, the number of the clock signals is reduced and thus the power consumption of the GOA circuit is also reduced. 
         [0012]    According to an aspect of the exemplary embodiments, this is provided a gate driver. The gate driver includes a plurality of gate driver on array (GOA) units. Each of the GOA unit includes a main driving circuit, a starting signal output circuit, and a plurality of gate driving circuits. The main driving circuit includes a first transistor, a second transistor, and a third transistor. The source of the first transistor is configured to receive a starting signal and the gate of the first transistor is configured to receive a first triggering clock signal. The gate of the second transistor is configured to receive a second triggering clock signal. The main driving circuit has a first control node and a second control node and is configured to generate a charging signal on the first control node and generate a control signal on the second control node in response to the starting signal, the first triggering clock signal and the second clock signal. The starting signal output circuit includes a fourth transistor receiving the charging signal to output an intermediate signal and a fifth transistor receiving the control signal to deactivate the intermediate signal. Each of the gate driving circuit includes a sixth transistor receiving the charging signal to output a gate driving signal and a seventh transistor receiving the control signal to deactivate the gate driving signal. 
         [0013]    According to another aspect of the exemplary embodiments, the starting signal is another intermediate signal transferred from a GOA unit of a previous stage or a starting signal provided by a gate driving control chip. 
         [0014]    According to another aspect of the exemplary embodiments, the first triggering clock signal and the second triggering clock signal are inversed. 
         [0015]    According to another aspect of the exemplary embodiments, the main driving circuit further comprises an eighth transistor, a ninth transistor, and a tenth transistor, and wherein when the first transistor is turned on by the first triggering clock signal, the eighth transistor, the ninth transistor, and the tenth transistor are turned on such that the charging signal is generated on the first control node and the control signal is generated on the second control node. 
         [0016]    According to another aspect of the exemplary embodiments, each of the sixth transistors of the gate driving circuits comprises a source, a drain, and a gate, wherein the sources of the sixth transistors are respectively electrically connected to different clock signals, the gates are electrically connected to the charging signal, and wherein the drains of the sixth transistors sequentially output a gate driving signal when the sixth transistors are turned on in response to the clock signals. 
         [0017]    According to another aspect of the exemplary embodiments, each of the seventh transistors of the gate driving circuits comprises a source, a drain, and a gate, wherein the sources of the seventh transistors are respectively electrically connected to the drains of the sixth transistors, the drains of the seventh transistors are electrically connected to a voltage source, the gates of the seventh transistors receive the control signal, and wherein the seventh transistors deactivate the gate driving signals by conducting the first voltage source when the seventh transistors are turned on in response to the control signal. 
         [0018]    According to another aspect of the exemplary embodiments, the fourth transistor of the starting signal output circuit comprises a source, a drain, and a gate, wherein the source of the fourth transistor is electrically connected to the second triggering clock signal, the gate of the fourth transistor receives the charging signal, and wherein when the fourth transistor is turned on by the second triggering clock signal, the drain of the fourth transistor outputs the starting signal. 
         [0019]    According to another aspect of the exemplary embodiments, the fifth transistor of the starting signal output circuit comprises a source, a drain, and a gate, wherein the source of the fifth transistor is electrically connected to the drain of the fourth transistor, the drain of the fifth transistor is electrically connected to the first voltage source, and the gate of the fifth transistor receives the control signal, and wherein when the fifth transistor is turned on by control signal, the fifth transistor deactivate the starting signal by conducting the first voltage source. 
         [0020]    According to another aspect of the exemplary embodiments, each of the GOA unit comprises a sequential-scan transistor and a reversed-scan transistor, respectively configured to receive a sequential-scan control signal and a reversed-scan control signal to control the GOA unit to operate in a sequential-scan mode or a reversed-scan mode. 
         [0021]    According to another aspect of the exemplary embodiments, a liquid crystal display comprises a gate driver. The gate driver includes a plurality of gate driver on array (GOA) units. Each of the GOA unit includes a main driving circuit, a starting signal output circuit, and a plurality of gate driving circuits. The main driving circuit includes a first transistor, a second transistor, and a third transistor. The source of the first transistor is configured to receive a starting signal and the gate of the first transistor is configured to receive a first triggering clock signal. The gate of the second transistor is configured to receive a second triggering clock signal. The main driving circuit has a first control node and a second control node and is configured to generate a charging signal on the first control node and generate a control signal on the second control node in response to the starting signal, the first triggering clock signal and the second clock signal. The starting signal output circuit includes a fourth transistor receiving the charging signal to output an intermediate signal and a fifth transistor receiving the control signal to deactivate the intermediate signal. Each of the gate driving circuit includes a sixth transistor receiving the charging signal to output a gate driving signal and a seventh transistor receiving the control signal to deactivate the gate driving signal. 
         [0022]    According to another aspect of the exemplary embodiments, the starting signal is another intermediate signal transferred from a GOA unit of a previous stage or a starting signal provided by a gate driving control chip. 
         [0023]    According to another aspect of the exemplary embodiments, the first triggering clock signal and the second triggering clock signal are inversed. 
         [0024]    According to another aspect of the exemplary embodiments, the main driving circuit further comprises an eighth transistor, a ninth transistor, and a tenth transistor, and wherein when the first transistor is turned on by the first triggering clock signal, the eighth transistor, the ninth transistor, and the tenth transistor are turned on such that the charging signal is generated on the first control node and the control signal is generated on the second control node. 
         [0025]    According to another aspect of the exemplary embodiments, each of the sixth transistors of the gate driving circuits comprises a source, a drain, and a gate, wherein the sources of the sixth transistors are respectively electrically connected to different clock signals, the gates are electrically connected to the charging signal, and wherein the drains of the sixth transistors sequentially output a gate driving signal when the sixth transistors are turned on in response to the clock signals. 
         [0026]    According to another aspect of the exemplary embodiments, each of the seventh transistors of the gate driving circuits comprises a source, a drain, and a gate, wherein the sources of the seventh transistors are respectively electrically connected to the drains of the sixth transistors, the drains of the seventh transistors are electrically connected to a voltage source, the gates of the seventh transistors receive the control signal, and wherein the seventh transistors deactivate the gate driving signals by conducting the first voltage source when the seventh transistors are turned on in response to the control signal. 
         [0027]    According to another aspect of the exemplary embodiments, the fourth transistor of the starting signal output circuit comprises a source, a drain, and a gate, wherein the source of the fourth transistor is electrically connected to the second triggering clock signal, the gate of the fourth transistor receives the charging signal, and wherein when the fourth transistor is turned on by the second triggering clock signal, the drain of the fourth transistor outputs the starting signal. 
         [0028]    According to another aspect of the exemplary embodiments, the fifth transistor of the starting signal output circuit comprises a source, a drain, and a gate, wherein the source of the fifth transistor is electrically connected to the drain of the fourth transistor, the drain of the fifth transistor is electrically connected to the first voltage source, and the gate of the fifth transistor receives the control signal, and wherein when the fifth transistor is turned on by control signal, the fifth transistor deactivate the starting signal by conducting the first voltage source. 
         [0029]    According to another aspect of the exemplary embodiments, each of the GOA unit comprises a sequential-scan transistor and a reversed-scan transistor, respectively configured to receive a sequential-scan control signal and a reversed-scan control signal to control the GOA unit to operate in a sequential-scan mode or a reversed-scan mode. 
         [0030]    According to another aspect of the exemplary embodiments, the transistors can be P-channel metal oxide semiconductor (PMOS) transistors or N-channel metal oxide semiconductor (NMOS). 
         [0031]    In contrast to the prior art, which needs to utilize 6 or 8 clock signals, the present disclosure utilizes two inversed clock signals and the starting signal to control the charging time and discharging time of the GOA circuit. Furthermore, the present disclosure utilizes 3 or 4 addition clock signals to control the output of the gate driving signals. Therefore, the present invention merely utilizes 5 or 6 clock signals to achieve the same effect of a conventional GOA circuit. In other words, the present disclosure may reduce the number of clock signals used in the gate driver and reduce the power consumption of the GOA circuit. 
         [0032]    These and other features, aspects and advantages of the present disclosure will become understood with reference to the following description, appended claims and accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]      FIG. 1  is a diagram of a conventional single-state GOA circuit; 
           [0034]      FIG. 2  is a diagram of a conventional two-stage GOA circuit driven by six clock signals; 
           [0035]      FIG. 3  is a timing diagram corresponding to operations of the GOA circuit shown in  FIG. 2 ; 
           [0036]      FIG. 4  is a diagram of a single-stage GOA circuit of a first exemplary embodiment; 
           [0037]      FIG. 5  is a timing diagram corresponding to operations of the GOA circuit shown in  FIG. 4 ; 
           [0038]      FIG. 6  is a diagram of a single-stage GOA circuit of a second exemplary embodiment; and 
           [0039]      FIG. 7  is a timing diagram corresponding to operations of the GOA circuit shown in  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0040]    Embodiments of the present invention are described in detail with the technical matters, structural features, achieved objects, and effects with reference to the accompanying drawings as follows. It is clear that the described embodiments are part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments to those of ordinary skill in the premise of no creative efforts obtained, should be considered within the scope of protection of the present invention. 
         [0041]      FIG. 4  is a diagram of a single-stage GOA circuit  400  of a first exemplary embodiment of the present disclosure. In this exemplary embodiment, P-channel metal oxide semiconductor (PMOS) transistors are used to realize the single-stage GOA circuit  400  and the entire circuit requires five clock signals. The five clock signals includes a first triggering clock signal XCKL and a second triggering clock signal CKL. In addition, the five clock signals further include three clock signals CK 1 , CK 2  and CK 3  for control the output of the gate driving signals. The first triggering clock signal XCKL and the second triggering clock signal CKL are inversed. Furthermore, Vss and VDD respectively represent a low voltage source and a high voltage source. ST(n−1) represents a starting signal transferred from a previous stage of GOA circuit or could be called as an intermediate signal. Here, if the GOA circuit  400  is the first stage of GOA circuit, a starting signal STV, which is provided by a scan driving chip or a timing controller chip, is inputted to the GOA circuit  400  instead of ST(n−1). 
         [0042]      FIG. 5  is a timing diagram of operations of the GOA circuit shown in  FIG. 4 . As shown in  FIG. 5 , the waveforms of the clock signals CK 1 -CK 3  do not have an overlap in the low-voltage portion. In addition, the frequency of each of the clock signals CK 1 -CK 3  is double of the frequency of the first triggering clock signal XCKL or the second triggering clock signal CKL. The frequency of the first triggering clock signal XCKL is the same as that of the second triggering clock signal CKL. However, the first triggering clock signal XCKL and the second triggering clock signal CKL are inversed (which means they have inversed phases). 
         [0043]    Please refer to  FIG. 4  in conjunction with  FIG. 5 . The correspondences among the gate driving signals, the first triggering clock signal XCKL, the second triggering clock signal CKL and the clock signals CK 1 -CK 3  can be understood from  FIG. 4  and  FIG. 5 . The operations of the GOA circuit  400  are illustrated as follows: 
         [0044]    As shown in  FIG. 4 , the GOA circuit  400  comprises a main driving circuit  420  and an output circuit  450 . The main driving circuit  420  comprises a first transistor T 41 , a second transistor T 42 , a third transistor T 43 , an eighth transistor T 44 , a ninth transistor T 45 , and a tenth transistor T 46 . The source of the transistor T 43  receives a starting signal ST(n−1) from another GOA circuit of a previous stage. As previously mentioned, if the GOA circuit  400  is the first stage, the transistor T 43  receives a starting signal STV. After receiving the starting signal, the node Q is charged to generate a charging signal Q(n). The gate of the transistor T 42  receives the second triggering clock signal CKL and the gate of the transistor T 41  receives the first triggering clock signal XCKL to control the voltage level of the node Q in cooperation with the intermediate (starting) signal ST(n−1). 
         [0045]    As shown in  FIG. 4 , the output circuit  450  comprises a starting signal output circuit  451  and three gate driving circuits  452 ,  453  and  454 . The starting signal output circuit  451  receives the charging signal Q(n) of the node Q to output the starting signal ST(n) and further receives a control signal K(n) from the node K to deactivate the starting signal. The output circuit  450  comprises a source to receive the second triggering clock signal CKL and three other sources to receive the clock signals CK 1 -CK 3 . 
         [0046]    Specifically, the transistor T 41  comprises a source, drain, and a gate. The source receives the starting signal ST(n−1) from a previous stage and the gate receives the first triggering clock signal XCKL. The charging period of the GOA circuit  400  is a time period when the starting ST(n−1) and the first triggering clock signal XCKL are both in a low voltage level. In this time period, the transistor T 41  is turned on and the drain of the transistor T 41  is in a low voltage level such that the transistors T 44 , T 45  and T 46  are sequentially turned on. In this way, the node Q is charged to a low voltage level and thus the charging signal Q(n) is established. 
         [0047]    The source of the transistor T 42  is electrically connected to the drain of the transistor T 41 . The drain of the transistor T 42  is electrically connected to the source of the transistor T 43 . The gate of the transistor T 42  is electrically connected to the second triggering clock signal CKL. The drain of the transistor T 43  is electrically connected to a voltage source VDD. The gate of the transistor T 43  is electrically connected to the node K. At this time, the node K may be charged to generate a control signal K(n). The control signal K(n) turns on the transistor T 43  and thus the drain of the transistor T 43  is electrically connected to the voltage source VDD such that the node K and the node Q have different voltage levels. 
         [0048]    When the first triggering clock signal XCKL corresponds to a high voltage level and the second triggering clock signal CKL corresponds to a low voltage level, the GOA circuit  400  is switched into a discharging period. In this time period, the voltage level of the node Q goes down such that the transistor T 42  is turned off. In addition, the transistor T 42  is turned on by the second triggering clock signal CKL and the voltage source VDD is electrically connected to the source of the transistor T 42  through the transistor T 43 (as previously mentioned, the transistor T 43  is also turned on). 
         [0049]    As shown in  FIG. 4 , the starting signal output circuit  451  comprises a fourth transistor M 3  and a fifth transistor M 5 . The source of the fourth transistor M 3  receives the second triggering clock signal CKL and the gate receives the charging signal Q(n). When the fourth transistor M 3  is turned on by the second triggering clock signal CKL, the drain of the fourth transistor M 3  generates a starting signal ST(n), the above-mentioned intermediate signal, for a next stage. 
         [0050]    The fifth transistor M 5  of the starting signal output circuit  451  comprises a source, a drain, and a gate. The source of the fifth transistor M 5  is electrically connected to the drain of the fourth transistor M 3 , the drain of the fifth transistor M 5  is electrically connected to the voltage source VDD, and the gate of the fifth transistor M 5  is electrically connected to the node K. When the fourth transistor M 3  is turned on, the fifth transistor M 5  is turned off. In addition, when the fifth transistor M 5  is turned on by the control signal K(n), the drain of the fifth transistor M 5  is electrically connected to the voltage source VDD and the starting signal ST(n) is deactivated. 
         [0051]    Each of the gate driving circuits  452 ,  453  and  454  comprises a sixth transistor M 6  and a seventh transistor M 8 . The sixth transistor M 6  of each of the gate driving circuits  452 ,  453  and  454  comprises a source, a drain, and a gate. When the GOA circuit  400  is in the charging period, the sixth transistor M 6  is turned on by the charging signal Q(n). The sources of the sixth transistors M 6  respectively receive the clock signals CK 1 -CK 3  and the gate driving signals G(3n), G(3n+1) and G(3n+2) are sequentially generated at the drains of the sixth transistors M 6  according to the timing of the clock signals CK 1 -CK 3 . 
         [0052]    The seventh transistor M 8  of each of the gate driving circuits  452 ,  453  and  454  comprises a source, a drain, and a gate. The sources of the seventh transistors M 8  are respectively electrically connected to the drains of the sixth transistors M 6  of the gate driving circuits  452 ,  453  and  454 . The drains of the seventh transistors M 8  are all electrically connected to the voltage source VDD. The gates of the seventh transistors M 8  are all electrically connected to the node K. When the sixth transistors M 4  of the gate driving circuits  452 ,  453  and  454  are turned on, the seventh transistors M 8  are turned off such that the gate driving signals G(3n), G(3n+1) and G(3n+2) are not affected. 
         [0053]    When the seventh transistors M 8  of the gate driving circuits  452 ,  453  and  454  are turned on by the control signal K(n), the sixth transistors M 4  of the gate driving circuits  452 ,  453  and  454  are turned off and thus the drains of the seventh transistors M 8  are electrically connected to the voltage source VDD such that the gate driving signals G(3n), G(3n+1) and G(3n+2) are deactivated. 
         [0054]      FIG. 6  is a diagram of a single-stage GOA circuit according to a second exemplary embodiment. In response to various scanning formats of the display device, a sequential scan function and a reversed scan function are included in the second exemplary embodiment. In the GOA circuit  600  shown in  FIG. 6 , two signals SF and SR are introduced to control the scanning directions. The signals SF and SR are both direct-current (DC) signals. In general, when one of the signals SF and SR is in a low voltage level, the other one of the signals SF and SR is in a high voltage level. In addition, when the signal SF is in a low voltage level and the signal SR is in a high voltage level, the GOA circuit is in a sequential scan mode, which means that the gate lines are sequentially driven through an increasing number of the stages of the GOA circuits (e.g., through stage  1 , stage  2 , stage  3 , . . . , stage n). On the other hand, when the signal SF is in a high voltage level and the signal SR is in a low voltage level, the GOA circuit is in a reversed scan mode, which means that the gate lines are sequentially driven through an decreasing number of the stages of the GOA circuits (e.g., through stage n, stage n−1, stage n−2, . . . , stage  1 ). 
         [0055]      FIG. 7  is a timing diagram illustrating different scanning modes of the GOA circuit shown in  FIG. 6 . Please refer to  FIG. 7  in conjunction with  FIG. 6 . From  FIG. 7 , the timing correspondences among the signals SF and SR, the gate driving signals, the first triggering clock signal XCKL, the second triggering clock signal CKL and the clock signals CK 1 -CK 3  can be understood. The operations of the GOA circuit  600  of the second exemplary embodiment are illustrated as follows: 
         [0056]    In the basis of the first exemplary embodiment, the GOA circuit  600  comprises a main driving circuit  620  and an output circuit  650 . The main driving circuit  620  comprises the same six transistors as the first exemplary embodiment. In addition, the GOA circuit  620  further comprises a sequential-scan transistor T 61  and a reversed-scan transistor T 62  respectively receiving the scanning direction control signals SF and SR. In addition, the source of the transistor T 61  receives a starting signal ST(n−1) from a previous stage and the source of the transistor T 62  receives a starting signal ST(n+1) from a next stage. In this way, the GOA circuit  600  is controlled to operate in a sequential scan mode or a reversed scan mode. The other operations of the GOA circuit  600  have been illustrated in the first exemplary embodiment, and redundant illustrations are omitted here. 
         [0057]    Above are embodiments of the present invention, which does not limit the scope of the present invention. Any modifications, equivalent replacements or improvements within the spirit and principles of the embodiment described above should be covered by the protected scope of the invention. 
         [0058]    In contrast to the prior art, the present disclosure utilizes two inversed clock signals and the starting signal to control the charging time and discharging time of the GOA circuit. Furthermore, the present disclosure utilizes 3 or 4 addition clock signals to control the output of the gate driving signals. Therefore, the present invention merely utilizes 5 or 6 clock signals to achieve the same effect of a conventional GOA circuit. In other words, the present disclosure may reduce the number of clock signals used in the gate driver and reduce the power consumption of the GOA circuit. 
         [0059]    While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.