The current generation of 3DTV sucks for lots of reasons, not the least of which is that it's not really 3D like a hologram is. Recognizing that true holographic video is a long way off, MIT has developed a glasses-free 3D stacked LCD display it's calling a Tensor Display that can make some of that magic happen.
The difference between the pseudo 3D that we see while wearing those ridiculous glasses at the movies and actual 3D images is perspective. With pseudo 3D, you get a sense of depth, that some things are farther away and some things are nearer. With actual 3D, you get the depth thing, but you can also view multiple perspectives of an object by changing your position relative to the screen. This is what pseudo 3D doesn't do, and what MIT researchers are trying to make happen with their new display.
In order to duplicate some of the best features of holographic TV (multiple perspectives, no glasses) without actually having to make a holographic TV, MIT is instead using a series of LCD panels stacked on top one another that it's calling a Tensor Display. The bottom LCD displays a series of patterns that interact with slightly different patterns from a second LCD on top to create 3D images. By refreshing the displays 1,000 times every second, the system can project hundreds of perspectives at once, allowing you to move around and see different things from different angles.
Unfortunately, we don't have commercial 1,000 hertz displays to do this with, so MIT went crazy and added a third display to the mix to drop the necessary refresh rate down to about 360 Hz. Calculating the way patterns from three displays interact with each other to create 3D images is exponentially more complex than working out the interactions between two displays, but there are some smart kids at that school, and they figured out that much of the content of a 3D scene doesn't really change all that much, allowing them to trim down the amount of data and computation required.
The three patterns in the image above, when displayed at 360 Hz on a series of three stacked LCDs, combine to produce a coherent, high-resolution, multiperspective 3-D image. The image on the bottom right roughly illustrates the composite image that would reach one eye at one viewing angle.
The advantage of using LCDs over some fancy new holographic display technology is that LCDs are cheap, they're available, and they're very robust. To really make a convincing 3D illusion, the display refresh rate of each panel will need to be significantly faster, at about 360 Hz, but considering it was just a few years ago that 120 Hz TVs showed up and 240 Hz TVs are on the market now, it's reasonable to expect that 360 Hz will soon be available. Otherwise, all you need to make a Tensor Display work is some clever math, and MIT has figured all that out already.
A prototype of MIT's Tensor Display will go on, uh, display, at Siggraph 2012 in LA next month, but in the meantime, the video below gives a pretty good overview of how it works.