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Apple patents glasses-free, 3-D projection technology

Apple has been granted a U.S. patent for a new 3-D projection technology that enables multiple viewers to watch 3-D without the glasses.

Although quite complex, its design concept is described simply as providing “highly effective, practical, efficient, uncomplicated and inexpensive auto-stereoscopic 3-D displays that allow the observer complete and unencumbered freedom of movement.”

The term “auto-stereoscopic” means without 3-D glasses, which has become the Holy Grail of 3-D imaging. Apple’s patent states, “Most voyages into virtual reality are currently solitary and encumbered ones: Users often wear helmets, special glasses or other devices that present the 3-D world only to each of them individually.”

This, Apple notes, is less than ideal, with the added understatement that “observers generally do not like to wear equipment over their eyes.”

Apple’s new technology tracks TV viewers’ position and movement, and then uses that information to guide the projection of pixels onto “a projection screen having a predetermined, angularly responsive reflective surface function.”

That means each projected pixel is beamed onto a textured, reflective screen in such a way as to reflect into the eyes of each viewer at angles that separate the image into left and right views. This produces the 3-D effect.

The patent describes a method whereby each pixel is aimed at a curved surface, where it reflects onto the correct eyeball. As a viewer moves in relation to the screen, the tracking sensor captures their individual view. That movement information causes the projection angle to change for that viewer.

While other computer manufacturers have been involved in auto-stereoscopic research and development, Apple has successfully summarized their work and directly addressed the limitations in three key areas.

The first, volumetric displays, presents images that “appear ghosted or transparent,” according to the patent. It also addresses the parallax barrier method, which “typically requires the observer to remain stationary in one location,” as well as dynamically presented holographic images that require “far greater computational ability and bandwidth than is generally required for (other auto-stereoscopic displays) … in real time and at commercially acceptable costs.”

Apple’s patent also describes methods for allowing viewers to virtually interact with the display by manipulating 3-D projections, in addition to what it refers to as “holographic acceleration.” This means that the displayed image can “move relative to the observer correspondingly faster than the observer’s actual movement or displacement,” with the level of acceleration determined by a “selected factor.”

No information was provided about when Apple’s 3-D display technology might be brought to market.