A holographic display is a display that uses LED light on a moving fan with at high speed, to create a three-dimensional (3D) image in space.
True holographic displays create images that conform to the six depth cues by which we recognize 3D views in the real world:
- Perspective: Objects farther away appear smaller.
- Occlusion: A closer object may obscure objects in the distance.
- Stereoscopic vision: Two viewpoints get a different view of an image, as human eyes do.
- Motion Parallax: Perspective changes as a viewpoint moves.
- Convergence: Two points cross on viewing closer objects, as human eyes do.
- Accommodation: Lenses change focus depending on an object’s distance within the image.
Commonly, images created by holographic displays as well as 3D images that are recorded onto typically 2D holographic media are called holograms. Technically, however, a hologram is the recording of a holographic image on a medium and an apparently freestanding 3D image created by a holographic display is called a holographic image.