Apple has filed a patent for an autostereoscopic projection system that could provide "highly effective, practical, efficient, uncomplicated, and inexpensive autostereoscopic 3D displays that allow the observer complete and unencumbered freedom of movement".

The patent shows how multiple users could watch the output in 3D (without glasses), with it stating:

"Most voyages into virtual reality are currently solitary and encumbered ones: users often wear helmets, special glasses, or other devices that present the 3D world only to each of them individually", but that "observers generally do not like to wear equipment over their eyes".

The patent fails to add, "unless your name is Bono".

Apple's patent points out how other autostereoscopic methods can lead to ghosting and transparency, and how users are usually required to keep still in a certain position.

Apple's method involves locating the viewers and then projecting the images using "a projection screen having a predetermined angularly-responsive reflective surface function".

The system would continue to monitor the viewers movements and adjust the pixel angle accordingly.

Whilst there are many big companies working on 3D tech at the moment, an Apple patent is bound to raise excitement levels, and not just with fanboys.

Although the Cupertino based giant wasn't first to the table with MP3 players, phones or tablets, it is difficult to argue that it hasn't managed to revolutionise and raise the bar in each of those categories.

A late arrival at the 3D arena, therefore, could still result in Jobs and co creating a major stir.

We'll be following this one closely.