An array of lasers which was columinated at the point of emission could do it (a well of 500nm cavities, with an LED module at the bottom could do it.

On the other hand: tensor displays are basically already there for what you say (http://www.youtube.com/watch?v=4r6lY8S4A6E).

It's a pretty solvable problem, we're just lacking the miniaturization (and power source) to make it practical.