The researchers laminated a flexible micro-lens array on top of the OLED-based ReFlex flexible smartphone they had demonstrated back in February to turn its bendable touch-display into a light-field capable interface. Combined with custom ray-tracing algorithms running on the phone's GPU, the flexible display renders holographic-like 3D images with motion parallax and stereoscopy to multiple simultaneous users without head tracking or glasses.
For this prototype, the researchers used 3D-printing to fabricate a matrix of 16,000 fish-eye lenses (only 0.75mm wide each) and cover a 1920x1080 full high-definition OLED display with it (403dpi with about a 0.063mm pixel pitch). Since each micro-lens dome covers 12-pixel wide sub-images (in fact a circular image made of approximately 80 pixels), they each contribute a pixel block of the entire scene from a particular virtual camera position with a 35º field of view (determined by the optical properties of the micro-lenses). Altogether, this yields a 160x104 resolution image floating in 3D a few centimetres off the actual screen, to be viewed from any angle.
As for the ReFlex smartphone, touch input allows for x,y input, while bend sensors allow users to control the z dimension, by squeezing the display.