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MIT Develops New Glasses-Free 3DTV

6 Aug, 2012 By: Chris Tribbey

Consumer electronics companies have spent a lot of time and money developing 3DTV that doesn’t require glasses, but it’s a team of researchers at the Massachusetts Institute of Technology that may have come up with the biggest break-through yet.

MIT Media Lab’s Camera Culture group has developed a glasses-free 3DTV technology — dubbed a Tensor Display — that uses three layered LCD panels that collectively produce a “coherent, high-resolution, multi-perspective” 3D image, without the need for glasses. Think of a 3D hologram that moves and still offers visual depth when the viewer changes perspective.

“Holography works. It’s beautiful; nothing can touch its quality,” said Douglas Lanman, a postdoc at the Media Lab. “The problem, of course, is that holograms don’t move. To make them move, you need to create a hologram in real time, and to do that, you need … little tiny pixels, smaller than anything we can build at large volume at low cost. So the question is, what do we have now? We have LCDs. They’re incredibly mature, and they’re cheap.”

The Tensor Display system is similar to the technology used in the glasses-free Nintendo 3DS portable gaming system, which uses two layered LCD screens to produce depth with slightly offset images. For their technology, the MIT team instead tied the images from the different screens together. The result is a glasses-free 3DTV effect that displays hundreds of perspectives to accommodate a moving viewer.

Issues do remain. Current, commercial LCD displays have refresh rates that max out at 240 hertz, and in order for Tensor Display to work correctly, a refresh rate of 360 hertz is required. The addition of a third LCD screen allowed the team to get the refresh rate required for the display down from 1,000 hertz to 360 hertz.

Gregg Favalora, with engineering consultant group Optics for Hire and co-chair of the SPIE (international society for optics and photonics) Stereoscopic Displays and Applications Conference, said the system could “greatly improve the realism, and image depth and physical simplicity of 3D display systems, particularly those that don’t require you to wear glasses.”

“It’s definitely suitable for commercial applications, because each component is commonplace, and it sounds easy to manufacture, so this ought to be something that a consumer-electronics company would license,” he said. “Honestly, this is a really big deal.”

A July 2012 report from the Consumer Electronics Association pins 2012 American TV shipments at 33 million, with 3DTV shipments accounting for 5.6 million of those units.

An affordable glasses-free 3DTV set that could accommodate large numbers of viewers would indeed be a “big deal,” if it can be done cheaply, according to Chris Chinnock, president of Insight Media, which oversees the cross-industry 3D@Home Consortium.

“There is no doubt that consumers would prefer to watch 3D without glasses,” he said. “But to get the best 3D experience today, you need to wear the glasses. [A quality glasses-free] option doesn’t really exist today. The limited viewing positions, loss of resolution in 3D mode vs. 2D mode, and higher cost for this technology makes them attractive only for enthusiasts at this time.

“As the MIT innovation illustrates, there is tremendous activity on all of the aspects of creating better 3D experiences, so I am optimistic that we will see 3DTVs and other products without glasses that meet the needs and requirements for a mass audience within a few years,” Chinnock added.

Ben Arnold, director of consumer technology industry analysis for The NPD Group, noted that a recent study done by his firm found that 79% of consumers considered glasses an obstacle to eventual ownership of a 3DTV, with 41% said it was a serious drawback.

“With that in mind, I was thinking we’d see a wider selection of viable glasses-free options at CES, but I estimated there were about as many as I had seen the year prior, so the technology doesn’t appear to be any closer to market than it was a few years ago,” he said. “I think the move to passive by many manufacturers helps make 3D a little more affordable, but the price of glasses was already declining pretty quickly.”

Glasses-free (or autostereoscopic) 3DTV isn’t new, but today’s commercially available version isn’t cheap, either.

Toshiba in May launched in the United Kingdom its Regza 55RZ1 55-inch 3DTV, a first-of-its-kind glasses-free 3DTV that relies on lenticular technology. Lenticular lenses, designed to display a different image to each eye, are built directly on the screen.

However, the 3DTV had an initial list price equal to $8,500, and offers a total of nine viewing angles that work with the 3D picture. A review of the set by TrustedReviews.com author John Archer noted that background objects looked out of focus and tests betrayed “a few signs of the physical structure of the lenticular lenses used on the screen’s surface to produce the 3D effect.” If a viewer moved their head too far left or right, images shifted “out of focus dramatically.”

“Overall the glasses-free 3D effect feels very clever, but still ultimately more like a work in progress than the sort of high-quality finished article a serious cinephile might spend [thousands on],” Archer wrote.

During the 2012 Consumer Electronics Show, Sony Electronics also showed off glasses-free 3DTVs, using lenticular technology. Commercial versions have yet to be announced.

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