3D Technology

3D technology gives a sense of depth to a 2D display. Your brain perceives the world in 3D automatically, processing the images received separately from your right eye and from your left eye. Faking 3D relies on sending slightly different images of the same scene to each eye and letting the brain do the processing. Today, there are three technologies that can create believable 3D effects.Passive Polarized Glasses
Polarization is a way to filter light so that only light beams of the same orientation are seen. One polarizing filter delivers one image to one eye, and a different polarizing filter delivers an image as seen from a slightly different direction to the other eye. The display device must be able to deliver images at different polarizations.

This technology is the cheapest method for 3D. However, the quality of the images are not that good. Many of the less expensive 3D televisions on the market now use this technology. Dolby, however, has developed a proprietary 3D system that does produce higher quality images — this system is used currently in many 3D movie theaters.

Active LCD Shutter Glasses
In this technology, eyeglasses have an LCD screen for each eye and an infrared receiver to synchronize the LCD screens with the movie being shown. Remember, a movie is simply still frames projected at a speed that your eyes see as motion. The active shutter method essentially closes one eye at a time, letting one eye see one frame and the other eye see the next. A film made for this method projects alternate frames of a scene seen from one angle, then from another angle. The LCDs turn off and on so quickly that the moments of blackness for one eye and then the other are not even perceived.

This technology is the 3D platform of choice today. Miniaturization of the components has begun. It’s true that bulky headsets are being used now in 3D movie theaters, but the main purpose for the size is not technology, but rather security — it’s hard to smuggle out one of those bulky headsets. Still, to see 3D, you must don a headset, and many people would rather not. For 3D without glasses, we must turn to the next technology …

Parallax Display
No eyeglasses are needed for this technology. The 3D effect is seen directly on a screen containing tiny angled edges or filters that can present different images when viewed at various angles. One limiting factor is the small number of viewing angles at which 3D can be perceived. When viewing the screen outside those 3D viewing angles, all that is seen is a blur of the two original images.

Many manufacturers and companies are developing this parallax technology, and its use is evolving even as you read this. 3D camera and gaming consoles are now being developed with parallax displays. Because no special eyeglasses are needed, this technology may turn out to be the primary one for 3D in the future.