Famicom 100Hz LCD Light Gun

[Jero32]

ya it was because lcd'' s always have some lag I think.

[133MHz]

It's not only the lag (besides, CRT based HDTVs also have lag which breaks target detection), but also LCD screens don't refresh like CRT screens do (no strobe effect) and also they don't emit light like a CRT does, so if you point the light gun to a flatscreen, it won't 'see' anything.

AFAIK, the NES light gun also depends on the CRT screen strobing effect to tell that it's really pointing to a TV screen.

[UglyJoe]

and also they don't emit light like a CRT does, so if you point the light gun to a flatscreen, it won't 'see' anything.

Flatscreen LCD, you mean?  I've tried using the zapper with my LCD and it does occasionally register shots (that is to say, it hits the target I was aiming for).  Maybe it can't see as well as it needs to, but I think it can still see.

[133MHz]

Whoa, cool! Judging by the ~16kHz low pass filter inside the Zapper I've thought that it used the CRT refresh as a way to ensure that the gun is pointing to the TV screen, since it won't work on a VGA monitor even if it's CRT unless you modify it.