Referring to 
The control switch circuit CSC is a circuit which controls the voltage of a node Q corresponding to the gate node of the pull-up transistor Tup and the voltage of a node QB corresponding to the gate node of the pull-down transistor Tdown and may include several switches (transistors).
The pull-up transistor Tup supplies a gate signal Vgate corresponding to a first level voltage (e.g., a high level voltage VGH) to a gate line GL through a gate signal output node Nout. The pull-down transistor Tdown supplies the gate signal Vgate corresponding to a second level voltage (e.g., a low level voltage VGL) to the gate line GL through the gate signal output node Nout. The pull-up transistor Tup and the pull-down transistor Tdown may be turned on at different timings.
The pull-up transistor Tup is electrically connected between a clock signal application node Nclk to which the clock signal CLK is applied and the gate signal output node Nout electrically connected to the gate line GL and is turned on or off by the voltage of the node Q.
The gate node of the pull-up transistor Tup is electrically connected to the node Q. The drain node or the source node of the pull-up transistor Tup is electrically connected to the clock signal application node Nclk. The source node or the drain node of the pull-up transistor is electrically connected to the gate signal output node Nout to which the gate signal Vgate is output.