18-Inch 3D LCD Screens
Rob Polyn sent in a story about a new 18" LCD screen using DTI to simulate 3D. An excerpt describes the technique:
"The second approach to true 3D animation is known as autostereoscopy (which DTI monitors utilize). In this method, two solid and unyielding images are produced for the user to view. These images are merged together, and if viewed by one eye, will appear to be two overlapping images, which don?t quite merge together correctly. However, when viewed with two eyes, autostereoscopy can produce vivid lifelike 3D images."
after a little more research i came up with this Philips research paper. (be sure to look at the nice diagrams in the slides).
the gist of it is this: much like 3d postcards, they use a grid of cylindrical lens over the LCD panel. each lens covers a specified number of real LCD pixels, 4 being a common number. since the lens is constructed to have the LCD pixel be at the focal point, when you look at the screen through the lens your eye will be directed towards one of the 4 pixels and not the others. thus the lens has turned 4 real pixels into one 3d pixel. (and dropped your resolution to 1/4th!) if you shift your viewing angle then you will look at a different one. if, like many people, you have two eyeballs which are separated by a few inches, then each eye will see a different image.
another way of thinking about it is to imagine that four zones of images are being projected out from each pixel to your eyes. as long as your eyes are in separate zones then you are okay. this is the case if you are sitting at normal reading distance. but if you get too far away (or have a head the size of a mouse) then your eyes will end up in the same zone and you lose the 3d effect.
philips has also done some innovative work to even out the resolution loss and improve the viewing angle.
- joshy
after reading how it works i now understand why it's so dim. if there is a 4:1 ratio of real pixels to 3d pixels, then each eye is only getting 1/4 the light it used to. guess they are going to have to beef up that backlight. then you can switch back to 2d and have a blinding image reflect of your face, just like in the movies. :)
Prop me up beside the jukebox if I die.