Its mind blowing laser keyboards looking good but still not real. Very cool indeed but it is only a concept for now, hopefully will be real in the future. I don’t believe you could type on air, but typing on flexible paper could work. Also maybe not purchasable for the vast market. I like the idea of being able to see the keys in the dark, but led lit switches in a silicone keyboard would do that without any of the disadvantages that a projection keyboard would suffer from.
Future Concept keyboard