Washington: Microsoft`s Applied Sciences Group has unveiled a new lens that could soon revolutionize glasses-free 3-D displays.
The lens, thinner at the bottom than at the top, steers light to a viewer`s eyes by switching light-emitting diodes along its bottom edge on and off.
Coupled with a backlight, this makes it possible to present different images to different viewers, or to create a stereoscopic (3-D) effect by showing different images to a person`s left and right eye.
"What`s so special about this lens is that it allows us to control where the light goes," Technology Review quoted Steven Bathiche, the director of Microsoft`s Applied Sciences Group, as saying.
Microsoft`s prototype display can deliver 3-D video to two viewers at the same time (one video for each individual eye), regardless of where they are positioned.
It can also show ordinary 2-D video to up to four people at the same time (one video for each person).
The 3-D display uses a camera to track viewers which enables it to steer light toward them.
The lens is thin and could thus be used in a standard liquid crystal display, said Bathiche.
Microsoft`s wedge lens is about 11 millimeters thick at its top, tapering down to about six millimeters at the bottom.
A traditional lens in a projector sits between a point of light and its focal point - the spot where the light is focused.
This is why viewer-tracking 3-D systems are usually so bulky.
However, the design of the wedge lens overcomes this problem, according to Bathiche.
He explained: "Instead of having light travel in air, it travels within the lens," he says. "It allows us to compress the distance between the projector and the screen."