To most people, the 3D effects of the 3DS' upper screen will forever remain the result of mysterious magic and mystery. To the more technical-minded, it's all about the 'parallax barrier'.
Tech On (via Engadget)has done another of their usual gadget tear-downs, this time with the 3DS which released in Japan over the weekend. You can see all its microchip guts, but the real interesting part for us is a close-up of the 3D screen under a microscope.
In it, you can see the black lines that make all that 3D trickery possible. Let us explain.
All stereoscopic 3D is based on the principle of mimicking your real-life depth of field by creating two slightly different views of the same scene, then separating these views so that each eye can only see the view intended for it.
The parallax barrier is like a clear LCD screen that lies over the top of the larger full-colour panel of the 3DS. When 3D is off the parallax barrier is clear, but when switched on voltage is passed through it making microscopic black lines appear.
These lines are the 'barriers' which block light in clever ways so as each of yours can only see alternating columns of pixels on the screen. Your left eyes sees 400 intermittent columns, and your right sees the other 400 (there are 800 horizontal rows of pixels in total).
Likewise, the images intended for each eye are split into alternating columns and so you see a 3D image.
Get it? No? Wikipidia it, then.