Great idea, much slimmer than ex using the tripwire/armour stand/trapdoor merhod or whatnot. Is it laggy? Also, lamps power on min 0.3s, so you'd have to figure out how to delay the pixel propagation. Since observers are 1 tick pulse only, the only smooth propagation would be 0.3s/frame, 3+1/3 fps.
If you happen to come across a display which runs at 0.4s/frame I'd be intrigued since I've own interest in powering a 4 block tall scrolling disp over 10 bps/1 wire. Best i got atm is a flat surface consisting of repeaters, which aren't that visible (vid at baslak98 youtube)
Keep up the good work!