Just in time for the new Star Wars film, it seems the technology from the originals is starting to come true. First it was lightsabers, then prosthetic arms like Luke Skywalker's, and now we're being promised hologram projectors like R2D2 - although maybe not as cute.

At the moment if you want to project three dimensional holograms into space you need to use mirrors or multiple sources placed around where the hologram is formed, so that light can interact from different directions.

Ostendo Technologies, a California start-up are dreaming much smaller. They have already demonstrated a prototype chip less than a centimeter long and a lens that fits on the palm of your hand. This tiny apparatus can, they say, control the color and brightness of enough LED beams to light up a million pixels on a screen with a 1.2m diagonal. Their short term goal is to put these into smart phones in the next year so that people can project videos on any handy surface. Having already created a 5000dpi projector, 20 times what is used in iPads, this part of Ostendo's plan looks well under way.

However, the more ambitious goal, which Ostendo's founder Hussein El-Ghoroury hopes to achieve as soon as 2016, is to create three dimensional displays projected from a single phone. Ostendo has wowed journalists with a demonstration of 3-D spinning dice that allow the viewer to move their position while the dice continue to look consistent. “Imagine if everything coming back to you was in 3D—all of your shopping, all of your gaming, every way you retrieve data,” El-Ghoroury said.

What Ostendo are not revealing is how they manage to project these images onto the air from a single direction. Traditional holograms work by having laser light from different directions interfere with each other. The idea was an unexpected side effect of the quest to improve X-Ray microscopy. 

However, unless Ostendo are going to require people to use two smartphones placed well away from each other, they will need something quite different if they're going to produce three dimensional Princess Leias. What that might be, no one knows, although rumors are circulating that bigger players are on board with the idea, or a competing version. Given the failure of past 3-D technologies, some people are skeptical that this is more than hype.

Meanwhile a Polish company promising holograms on tablets are even more explicitly appealing to Star War enthusiasts, calling itself Leia Display Systems. However, they are being a little more forthcoming with how they plan to achieve their goal, saying they will use a field of water vapor as a screen.