https://wiki.archlinux.org/index.php/SANE
https://www.archlinux.org/packages/extra/x86_64/sane/
Install sane
yaourt -S sane --noconfirm
You may need to unplug and plug the scanner in order to make sane discover it.
List the scanner devices detected by sane:
scanimage -L
Start scanning:
scanimage --format=png > "1.png"
Note: You may need to add the param --device $DEVICE if sane detects more than one device, where $DEVICE is the desired device.