MIT develops holographic, glasses-free 3D TV

ORIGINAL:  Extremetech.com

By Paul Lilly on July 12, 2012 at 5:44 am

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The masterful engineers at the Massachusetts Institute of Technology (MIT) are busy working on a type of 3D display capable of presenting that elusive third dimension without any eye gear. We say “elusive” because what you’ve been presented at your local cinema (with 3D glasses) or on your Nintendo 3DS console (with your naked eye) pales in comparison to what these guys and gals are trying to develop: a truly immersive 3D experience, not unlike a hologram, that changes perspective as you move around.

Today’s 3D technology falls short in a number of ways. The most obvious is the need for special viewing glasses that may be uncomfortable to wear, darken the on-screen imagery, and are prone to annoying finger smudges that are a bear to wipe off.

Nintendo’s 3DS console is one such device that dispenses with the need for eye gear by using two layered liquid crystal diode (LCD) screens to create the illusion of depth. Offset images create a sense of perspective, while alternating light and dark bands emanating from the bottom screen ensure your eyeballs only take in the images they’re supposed to at any given moment. It’s a serviceable recipe for rudimentary glasses-free 3D, albeit on a small scale suitable for handheld consoles.

In order to produce a convincing 3D illusion, MIT's three-panel technology requires a display with a 360Hz refresh rate.

What the researchers at MIT have come up with is a more sophisticated way to paint a 3D scene that changes perspective as you move around. It does away with the need to sit in a fixed, optimal position (think of how in a movie theater, everyone views the same perspective regardless of where they sit), and in fact could ultimately encourage changing your viewing angle, depending on how creative developers get with the technology. To give you an example, imagine leaning left in your chair to spy an enemy crouched behind a crate in a first-person shooter (FPS).

The project is called High Rank 3D (HR3D). To begin with, HR3D involved a sandwich of two LCD displays, and advanced algorithms for generating top and bottom images that change with varying perspectives. With literally hundreds of perspectives needed to accommodate a moving viewer, maintaining a realistic 3D illusion would require a display with a 1,000Hz refresh rate.

To get around this issue, the MIT team introduced a third LCD screen to the mix (pictured above). This third layer brings the refresh rate requirement down to a much more manageable 360Hz. More importantly, it means short term application of this technology is possible. Currently, TV technology maxes out at 240Hz, so a high-speed panel in the 360Hz range isn’t all that far-fetched.

The researchers plan to present a tri-panel prototype display at Siggraph. In the meantime, it’s worth carving out three and a half minutes of your time to watch the video below, which explains the technology in visual detail.