Scientists have created a 3D display that could mimic the Princess Leia hologram in Star Wars – even on mobile phones

Scientists have created a glasses-free, 3D display that could mimic the famous hologram projection of Princess Leia in the original 1977 Star Wars film.

The display is small and light enough to work on mobile phones, and produces images that appear in 3D even when viewed from different angles, the scientists said.

To make the device, researchers at Hewlett-Packard Labs in Palo Alto, California, built a transparent screen with tiny light emitting diodes (LEDs) around the edges. Light rays sent towards the centre encounter pixels that steer the light out of the screen in different directions.

Through careful control of the light, the device sends slightly different images to each eye, which are combined in the brain into a 3D object.

A prototype of the device, described in the journal Nature, can send light in 14 different directions, which is too few to give a smooth 3D effect. For that, the researchers are developing a more sophisticated device that sends light out in 64 different directions.

"In principle you would be able to move your head around the display, rotate your head in any direction, and still see a 3D image, much like what you see in Star Wars, with the famous hologram of Princess Leia," said David Fattal, who helped to create the device.

"If you were to display a 3D image of planet Earth with the north pole facing out of the screen, by turning your head around the display you'd be able to have a view of any country on the globe," he added.

Another HP researcher, Raymond Beausoleil, said the technology might first be used for low-cost 3D signs. "Perhaps in the not so distant future, it could make its way to smartphones, smart watches and tablets," he added.

In an accompanying article, Neil Dodgson, professor of graphics and imaging at Cambridge University's Computer Laboratory, said major challenges must be overcome before hologram-like displays are a reality on mobile devices. Key among these are whether the 3D effect comes at the expense of resolution and image quality.

"The examples given in the paper show that there is considerable work to be done to improve the quality to an acceptable level," he wrote.

Perfecting the displays and their manufacture could take a long time, Dodgson warns. "I am reminded of the nine-year development of Texas Instruments' digital micro-mirror device, now widely used in digital projectors, between the invention in 1987 and the first commercial product in 1996," he added.