Help me with target light gun project for LCD

[markdem]

Hi all, I have a idea for a project.
I would like to make a adapter for a rifle that I can shoot at my TV (no bullets of course), much like the old duck hunt game for a Nintendo. From what I have read on the internet, the old guns would work by blanking the screen, and drawing just the target white, then a photo diode in the gun would work out if it was pointing at the target. This sounds good, but I am only shooting at one target, the normal rings in rings type, which does not move, and will take up most of the screen.
I then read that some light guns used the sync and refresh rates to work out where the gun was pointing. Problem with this is, I have a LCD, which i don't think work the same way as a CRT.

My question is, what would be a good way of working this problem out? I guess i don't have to use a LCD to display the image. I need to have a very fine (.25mm) resolution in the detection of the position.

Any ideas?

Thanks

Mark

 

[markdem]

Re: Target light gun

Just read on the internet that the Nintendo Wii does what I am looking for. It does this by emitting two main beams of IR light out from a device that sits under the TV, and the remote uses that for a fixed reference in space. I understand how this can workout distance from the IR source, but how does it know where on the TV you are pointing at?

Thanks
Mark