Invention of the day: A true 3-D plasma display.

Most "3D" displays draw pseudo-3D images on a two-dimensional plane by utilizing the human binocular disparity (your eyes are several inches apart, and see a slightly different view). This device creates a true three-dimensional picture with infrared pulse laser light that creates a small dot of plasma (light-emitting ionized gas) in mid-air. Software controls the galvanometric mirrors that aim the laser pulses; any figure can be reproduced.

The display uses one pulse for each "pixel" - the plasma pixel has an emission time of about a nanosecond. The device can create about 100 dots per second, limiting the resolution of the display.

Most science fiction fans immediately think "Help me, Obiwan Kenobi. You're my only hope" when they think about three-dimensional displays that appear in mid-air.

Here's a related story.