If you've never had a screen with a broken backlight it might not be obvious, but without the light a normal TFT display is basically unreadable except in very

If you've never had a screen with a broken backlight it might not be obvious, but without the light a normal TFT display is basically unreadable except in very specific orientations due to the way the layers are sandwiched. You're probably looking for what's referred to as "transparent LCD", which I think still are not very nice to look at (Google has plenty of example pictures).