Parallax Barrier Help

I really want a glasses-free 3d display on my next Arduino project. I know parallax barriers are pretty simple but I want to create one like the 3ds how the barrier is on an lcd in front of the actual screen. So there a couple routes I can go. There are replacement screen available for the 3ds and the lg optimus which have that technology but I have no idea where to begin programming those. Also, I could just use a transparent lcd. I know you cant buy them transparent, but is taking off the backlight and layering two lcds gonna work? Will the one backlight be strong enough? Or is there another option I cant think of? Thank you in advance please let me know your thoughts. P.S. I want a screen size of about 4 inches but will compromise either way. Size is not that big of an issue.

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