Wikipedia
The Heliodisplay is an air-based display using principally air that is already present in the operating environment (room or space). The system developed by IO2 Technology in 2001 uses a projection unit focused onto multiple layers of air and dry micron-size atomized particles in mid-air, resulting in a two-dimensional display that appears to float (3d when using 3d content). This is similar in principle to the cinematic technique of rear projection and can appear three-dimensional when using appropriate content. As dark areas of the image may appear invisible, the image may be more realistic than on a projection screen, although it is still not volumetric. However the system does allow for multiple viewing and dual viewing (back and front) when combined with two light sources. The necessity of an oblique viewing angle +/- 30 degrees may be required for various configurations due the rear-projection requirement.
Heliodisplay can operate as a free-space touchscreen when the equipment is ordered as an interactive unit with embedded sensors in the equipment. The original prototype of 2001 used a PC that sees the Heliodisplay as a pointing device, like a mouse. With the supplied software installed, one can use a finger, pen, or another object as cursor control and navigate or interact with simple content. As of 2010, no computer or drivers are required. The interactive version ("i") of the heliodisplay contains an embedded processor that controls these functions internally for single touch, or multiple touch interactivity using an equipment mounted arrangement but without the IR laser field found on the earlier versions. The smaller Heliodisplay version is transportable at and is as big as a lunchbox (30 cm x 30 cm x 12 cm) similar to the 2002 version. The larger equipment such as the systems that project life-size people capable of image diagonals up to 2.3 m also have the same footprint, about the same size as a sheet of paper.
The air-based system is formed by a series of metal plates, and the original Heliodisplay could run for several hours although current models can operate continuously. 2008 model Heliodisplays use 80 ml to 120 ml of water per hour (most used for cooling), depending on screen size and user settings, although the medium is primarily air. Various versions of the heliodisplay work predominantly from the surrounding air (such as under museum environments) where there are negligible affect to the surrounding space. A tissue paper can be left on the exhaust side of the unit for a 24-hour period without any affect of moisture to it as compared to other mist or fog generating equipment that relies more on pumping a liquid or vaporizer and thereby affecting the surrounding air.
The Heliodisplay was invented by Mr. Dyner, who built it as a five-inch interactive prototype in 2000-2001 before patenting the free-space display technology. The original system used a CMOS camera and IR laser to track the position of a finger in mid-air and update the projected image to enable the first of its kind co-located display with mid-air controller interface. IO2 Technology commercialized the original versions along with improvements over the years in developing the product line. The Heliodisplay is sold directly worldwide by IO2 Technology with offices in The Bay Area of Northern California.