MIT researchers have cooked up a new glasses-free 3D system that supports multiple viewers watching from different perspectives, and relies on existing cheap technologies rather than expensive holograms. The Media Lab Camera Culture Group stacked multiple LCD panels on top of each other, each running at a high refresh rate, and which show slightly different perspectives of the same image or video frame, which the human eye adds up to a 3D picture.
Existing glasses-free 3D displays have butted up against significant issues which have limited their usefulness in the home environment. Some use cameras to track the user's eyes and adjust the angle of two slightly offset images being shown through a fresnel lens, such as Toshiba's F750 3D laptop, but the system only works with a single set of eyes.
Alternative approaches use multiple lenses to increase the number of simultaneously supported viewers, but generally require those people be in specific positions in relation to the screen in order for the effect to work. Holograms, meanwhile, are considerably more expensive than most current high-end displays.
What MIT has done is use straightforward, inexpensive LCD panels paired with clever processing. The system is similar to that used by the Nintendo 3DS, but uses three panels which collectively filter the light so that it changes depending on the angle of viewing. One technical requirement for smooth video is the refresh rate, which needs to be 360Hz - most high-end panels run at 240Hz at present, though going 50-percent faster shouldn't present manufacturers with too great a challenge.
The prototype can create a glasses-free 3D viewing angle of 20-degrees, but a special two-panel version with a special lens sheet in-between that has been boosted to 50-degrees. Heavy-duty graphics processing is required to manage the data feed, but the latest high-end video cards are capable of that. More details in the video below.