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 oparate as a free-space touchscreen when connected to a PC by a USB cable. A PC 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 the year 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 the same rear camera arrangement but without the IR laser field found on the earlier versions. Heliodisplay equipment is typically smaller, lighter, and more energy efficient than other comparables. The smaller version is transportable at ~9 pounds (4 kg) and is as big as a lunchbox (30cmx30cmx12cm) similar to the 2002 version. The larger equipment weights 70 lbs (31 kg) and takes up as much floor space as about a sheet of paper utilizing around 300W or that of a PC computer 
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 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 California.
The original M1 units produced by IO2 were advanced prototypes and proof-of-concept. These are the first Heliodisplay developed by the IO2 Technology. They have all the above said properties. But they have less fidelity than the future systems although adopted various ion-discharge plates  and showcased in 2003. This first generation Heliodisplay supported only a 22” image and utilized an IR light source and an IR camera to track the position of a finger for cursor controlling the images.
The second-generation M2 Heliodisplay supports a 30" image with 16.7 million colours and a 2000:1 contrast ratio. The interactive M2i version includes virtual touchscreen capability.
M3 and M30
The new third-generation M3 version launched on February 28, 2007  has the same basic specifications as the M2 but is said to be much quieter, with improved brightness and clarity and more stable operation with an improved tri-flow system.
Apart from displaying at a standard ratio of 4:3 in addition it also displays 16:9 widescreen ratio. There is also an interactive version called the M3i.
The M30 is the updated version of the M3, which fits into the current model numbering system, 30 designating the diagonal screen size.
M50 and M100
In late 2007, IO2 Technology introduced two larger Heliodisplays, the M50 and M100. The M50 has a 50" diagonal image, equivalent to displaying a life-size head-and-shoulders person. The M100 has a 100" diagonal image, equivalent to displaying a large full-body person (about 2 meters tall).
S and L and XL
In 2011 IO2 reintroduced the smaller format Heliodisplays along with the standard L(large) models that project approximately 2 meter tall image (for lifesize person projections). The L models can be placed on the floor as a standing tower and take up slightly more area that a sheet of paper (14 inches in diameter) and weigh in around 70 lbs (35 kg) allowing it to be moved around by one person. Power consumption for the base tower 2meter version is as energy efficient as the legacy models and consumes around 300 watts. The system is based on improvements to the M100, and similarly, the s (small) models over the legacy versions of the m30 both in image and user interface. The XL model is a separate system that supports larger format images beyond the 2 meter range. All units from 2009 have a simple interface with a single on/off button and power cord.
- David Bernstein. Making Something Out of Nothing. December 18, 2003.
- IO2 Technology intros floating M3 Heliodisplay screen
- IO2Technology M3
- The IO2 website
- "Interactive 3D Display: It's here!" article from OhGizmo.com
- Sci-fi projections Article from CBC, March 22, 2007
- "Wired Report: Look Ma, No Projection Screen". 2007. Retrieved 2007-03-25.
Early footage (~2002)
- Display of a wristwatch
- A famous clip showing the Heliodisplay's interactive navigation using a map display
- Display of a car's exterior