How 3-D TV Works

Lenticular Displays
This Toshiba display uses a lenticular film to direct light to the viewer's eyes, which creates a 3-D effect.
This Toshiba display uses a lenticular film to direct light to the viewer's eyes, which creates a 3-D effect.
AP Photo/Shinzuo Kambayashi

While 3-D technology is impressive, some people still want a solution that doesn't require them to wear glasses. There have been several attempts at creating a display capable of projecting images into a three-dimensional space. Some involve lasers, some project images onto a fine mist or onto artificial smoke, but these methods aren't that common or practical.

There's one way to create three-dimensional images that you may see in places like sports arenas or in a hotel during a big conference. This method relies on a display coated with a lenticular film. Lenticules are tiny lenses on the base side of a special film. The screen displays two sets of the same image. The lenses direct the light from the images to your eyes -- each eye sees only one image. Your brain puts the images together and you interpret it as a three-dimensional image.

This technology requires content providers to create special images for the effect to work. They must interlace the two sets of images together. If you were to try and view the video feed on a normal screen, you would see a blurry double image.

Another problem with lenticular displays is that it depends upon the audience being in a sweet spot to get the 3-D effect. If you were to move to the left or right from one of these sweet spots, the image on the screen would begin to blur. Once you moved from one sweet spot to another, the image would return to a cohesive picture. Future televisions may include a camera that tracks your position. The television will be able to adjust the image so that you're always in a sweet spot. Whether this will work for multiple viewers of the same screen remains to be seen.

Some people experience a feeling similar to motion sickness after watching a lenticular display for more than a few minutes. That's probably because your eyes have to do extra work as they deal with the discrepancy between focus and convergence. But on the other hand, you don't have to worry about losing an expensive pair of active glasses.

Will 3-D television become the next big trend or is it destined to be a fad that comes back every couple of decades? It's too early to say right now. But the technology continues to improve. It may not be long before you duck out of the way the next time a baseball player hits a line drive toward the camera.

Learn more about televisions and 3-D on the next page.

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