Infrared detection

Hi everyone,
I want to make a infra red detection like those used for "laser keyboard"
Do you have any ideas, shcematics, development kit or code example (PC) to suggest me ?
I need to detect forms such as fingers on a 40'' diagonal surface (maximum)
Also, I would like to project a display (projector) on the same surface : do you think it could be problematic for infra red detection ?
Thank you for your help
Kind regards
Wold

Welcome to ETO, woldrajh!

Not an easy nor simple task to make one yourself. Basics at: https://en.wikipedia.org/wiki/Projection_keyboard

State-of-the-art unit (that looks pretty cheap to me (and SMALL): **broken link removed**

Hi

Thank you for your answer. I am actually looking for a part could be integrated into a product more than a product. In this context a freeware code based on infra red detection by camera could be great. Anybody ?

Kind regards