A scan signal driver including: a plurality of stages for outputting scan signals and sensing signals, wherein a kth stage among the stages is connected to a kth scan signal line and a kth sensing signal line, and wherein the kth stage includes: a first output unit configured to output a scan clock signal input to a fit scan clock terminal to the kth scan signal line as a kth scan signal and to output a sensing clock signal input to a first sensing clock terminal to the kth sensing signal line as a k sensing signal when a pull-up node has a gate-on voltage; and a second output unit configured to output a carry clock signal input to a first carry clock terminal as a kth carry signal to a carry output terminal when the pull-up node has the gate-on voltage.