This technique, used with space between the grating and the image, is what they are using for glasses-free digital 3D screens. You could think of this as a com

This technique, used with space between the grating and the image, is what they are using for glasses-free digital 3D screens. You could think of this as a completely flat parallax barrier screen, only it's physically moved to show different views of the image. Autostereoscopy works because the angle of your two eyes does the moving for you (there are only two frames — one for the left eye view and one for the right eye view).