This question already has an answer here:
Is it possible to project an image into the eye, without wearing glasses or using a projection screen, which:
Appears to be on a focal plane in front of rather than behind the source
Appears larger in width/height than the source
The image doesn't need to be truly volumetric, appear when viewing from the side, appear to anyone other than the user, or display true black. Less ambitious than R2D2 :) Goal: take a smartphone-size device out of my pocket, put it on a cafe table, look down and see a floating image larger than the device.
Side view (image only visible to eye, not visible to person to the side): http://imgur.com/a/UPIW8
Example: smartphone with pseudo 3D using eye tracking and parallax: https://www.youtube.com/watch?v=xXRHuaO38bs&t=3m40s