How does this work?
Projecting an image of the keyboard? Probably a laser and a diffractive element
Then a camera detecting if anything (ie a finger) is blocking a particular key
Not so simple though, because when you press a key on the top of the keyboard, your hand blocks a major section of all the keys below. So it has to distinguish which key is actually being pressed.
From a consumer standpoint, a very stupid product because now I no longer have a tactile feel of a key being pressed, nor do I have the indents as a reference (on the F and J keys) for my fingers so I can type without looking. Nor do I want yet another device with more cables and a power outlet.
I agree -- probably terrible typing ergonomics. You probably have to keep your fingertips at least some distance above the table image, so that the tap is more evident to the reader. When I'm blazing at typing, my fingertips are generally off the keyboard, but as I slow down to think, my fingertips naturally come to rest, and as Cyrus says, re-confirm the home row position. Yuck.
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