Screen less video is a term which describes the system for transmitting visual information from a video source without the use of a screen. Screen less computing systems can be divided in to three types which are described below:
Retinal Display:
These are one of the screen less displays in which images are projected directly on to the retina. The light is not reflected from some intermediate object as in the visual image system but the it is directly projected on to retina. Even though computer works at the public places, with the use of this system it provides privacy because most snooping relies on viewing the same light as the person who is legitimately viewing the screen, and retinal direct systems send light only into the pupils of their intended viewer.
Visual Image:
It includes any screen less image that the eye can perceive. In the visual image screen less display systems light is reflected off some intermediate object before it reaches the retina but in the case of LCD panels the light is refracted from the back of the panel. Examples of the visual image screen less display are hologram, virtual reality goggles and heads up display in jet fighters.
Synaptic Interface:
Light is not used in this type of screen less video and the visual information is directly transmitted to the brain and it bypasses the eye. These systems are not implemented in humans but they had proved to be success in sampling usable video signals from the biological eyes of a living horse shoe crab through their optic nerves.
Screen less computing systems are very advanced technology and these are yet to be widespread among common people.