[TechniSol]

I believe there are emitters on one side and detectors on the other side opposite on both x and y axis. They could be staggered, but I see no benefit to that. The idea would be to rapidly pulse each emitter and then check for reception on the other side. If no signal is received on a particular sensor then you immediately scan the other axis to form a coordinate pair. This scanning is performed at a very high rate of speed. If you are detecting multiple inputs I suspect you would complete one axis scan and then the other noting each break. Now how you associate which x break with which y break I am clueless... Maybe with multi touch the only importance is figuring out whether the coordinates are converging or diverging like a pinch zoom gesture? I suppose it matters not as Kobo has(will?) not implemented multi-touch on their readers.

I would try just a little smoke to reveal the IR with the appropriate camera. Maybe hold it over a stick of incense or the like? I imagine it would need to be pitch black to see it as it's got to be pretty low power stuff and FAST.

Hudson Hawk! You're a man after my own heart, Ken. I can see you humming "Swingin' on a Star" as you disassembled that brand new Aura! ;p I completely fail to understand how people didn't get that movie.