March 20, 2013 at 6:42 PM ET
3-D TV might not have caught on as much as display makers hoped it would, but part of that has to be due to the uncomfortable, silly-looking glasses one always has to wear. Glasses-free 3-D seems to be the future, and research at HP is a huge leap beyond existing systems like the Nintendo 3DS.
In order to see in 3-D, each of our eyes must see a slightly different image. Usually they get different views by virtue of one being a few inches from the other. But when viewing a TV, they see the same thing on the screen — unless the screen sends a different image to each eye.
This can be done by blocking out images going to the "wrong" eye, which is what 3-D glasses do, or by having the display itself angle every other row of pixels ever so slightly so that they align with either the left or right eye — you may have experienced this on the most common glasses-free display out there, Nintendo's 3DS handheld game console.
But displays like the 3DS's have a small "sweet spot" where the 3-D effect works, and there is only one "view" of the content — moving your head doesn't change the perspective. Research at HP, led by David Fattal, has resulted in a far superior method that may eventually provide not only more sweet spots, but the ability to show content from dozens of angles.
It works by causing each pixel of an image to be sent in in several different directions, and with sophisticated control over the "diffraction grating" that does this, the image sent straight out can be different from the one sent a few degrees to the left or right. A little fine tuning allows for them to send different images to where they expect each eye will be as well.
The result is a display that can send different images in different directions, and if those images are different views on the same object, viewers see a 3-D picture, one that changes with their point of view. Up to 64 different angles could be shown with current technology, theoretically.
The wide field of view and relatively low power requirements of the display make it perfect for something like mobile phones — and unlike the display in the 3DS, it doesn't result in a darker final image than a traditional 2-D display would show.
But don't expect to see it in the next iPhone or Galaxy S. There are some tradeoffs.
For one thing, instead of processing and showing just one image, the device would now have to keep track of dozens — a major increase in processing power, RAM, and battery power would be necessary. It also wouldn't have the "Retina" resolution so many mobile users are used to.
It's still a promising technology, both for 3-D displays and other methods it may enable. Fattal et al.'s paper, "A multi-directional backlight for a wide-angle, glasses-free three-dimensional display," appeared Wednesday in the journal Nature.
Devin Coldewey is a contributing writer for NBC News Digital. His personal website is coldewey.cc.