A free-space display projects images into space, in both two and three dimensional formats. The device does not require the use of a projection screen or enclosure, which provides considerable flexibility. It is possible to set up a free-space display as a temporary installation or a permanent one, in settings which may vary from the living room to the street corner. Some companies have products available for sale, while others have them in development, or are working on refining existing products.
The size of the images projected by the device can vary. Some make use of lasers to create an image, while others may use powerful projectors and other devices. A free-space display may be able to project images into open air, or may require a backing like fog, mist, or smoke for the images to show up. The quality of images is also highly variable between manufacturers and production methods, an important consideration for customers.
Potential applications for this technology are considerable. It is possible to develop interactive displays that allow people to manipulate objects in free space. This can be useful for video gaming, advertising, and activities like telemedicine, where a doctor might want a set of controls with a more natural feel to steer a robot or look at medical imaging studies. A free-space display can also be used for on the street advertising that would not be limited to billboards and other flat surfaces, or for activities like special effects in a theatrical production.
Like other display technology, early free-space displays were expensive to produce, with poor image quality, including heavy pixelation and slow refresh rates that made images appear jerky. Investment in the technology by a number of competing companies created a drive to produce cheaper, bigger, and better technology. Two and three dimensional versions pose various challenges, such as the need to determine the optimal viewing angle, that manufacturers must consider in their research and development.
Companies that work with free-space display technology have a particular interest in systems that do not require any kind of projection medium. The ability to project an image quickly and easily with a portable or easily movable display system has numerous applications when it is not necessary to create a projection medium with fog or other materials. This design is extremely challenging, as free-floating images can be hard to see in bright or high contrast light conditions, which makes it difficult to develop effective technology.