Holographic projector technology use holograms rather than the graphic images to create projected images. They reflect special white light or laser light through holograms. The projected light displays two or three-dimensional pictures. While clear daylight lets you see some holograms, true 3-D pictures need a laser-based 3d holographic display projector.
You can see such pictures from different angles and view them in real perspective. Small versions of such projectors are in the development. Using this kind of projector, a smartphone could create a picture for the viewer in a blank space rather than on the small screen.
The main key to the operation of holographic projector technology is a hologram. Before the arrival of digital imaging, these holograms were patterns of films. The photographer took a particular source of light and split it into two parts. Half lightened the subject and half went immediately to the film, producing an interference pattern with light reflected from the subject. The holographic projector used same light and film to recreate a picture of the subject.
Holographic projector technology creates projected picture by refraction through an interference pattern, losing hardly every light, and operating more efficiently. They can be quite small and produce very little heat. This will make them perfect for eventual applications in the mobile electronic devices for which space is limited.
A real hologram projector with the light source shining through flat interference pattern can produce a picture that has three-dimensional features, but it is still plane. To produce a true 3-D image, a holographic projector can use the spinning mirror to reflect that picture to an observer. The mirror sends a picture corresponding to an angle from which the observer is seeing the subject. As observer will move around the subject and view it in different prospects, he will see a three-dimensional picture floating in the space.