Manufacturers focus on glasses-free, passive 3-D sets for sales

After a disappointing holiday season for 3-D TV sales, manufacturers were back at the recent CES in Las Vegas trying again. A big focus this year was getting rid of the 3-D glasses, one of the most unpopular aspects of current 3-D home systems. Another trend was a switch to less expensive passive 3-D glasses, enabling consumers to afford more than two sets of glasses to entertain their friends (another major hurdle to widespread adoption).

Called autostereoscopic TVs, glasses-free 3-D sets have become something of a holy grail for the industry, but the transition is not easy. A 3-D image depends on human eyes seeing two slightly different images. The easiest way to do this is to wear a set of glasses that can use the lenses to change or filter the image slightly.

Right now, active-shutter glasses do this by dimming each lens in rapid succession, while polarized 3-D filters use the glasses to show each eye a different image by filtering the light that each eye can see. To achieve this without glasses requires a special TV panel display. Most such displays today are too expensive and restrictive, reducing a weak 3-D effect to a fixed distance and angle for no more than two viewers.

At CES, several of the major TV manufacturers had prototype glasses-free 3-D TVs. LG had some portable displays; Sony had 47in and 55in models and a portable Blu-ray player; and Toshiba showed a 65in HDTV as well as a few portable Blu-ray players and a laptop. Still, no manufacturer announced a commercially available product.

A promising glasses-free demo came from iPont, a small Hungarian company. Its setup consisted of a 65in autostereoscopic 3-D display by Tridelity hooked to an iPont box. For the tests, iPont used clips from YouTube 3-D, designed for use with 3-D sets with glasses.

While the viewing angles were as limited as those of the major manufacturers, the depth of the images was much deeper and more compelling. Better yet, iPont’s 3-D box, the company said, was built with off-the-shelf parts.

Another CES trend in 3-D was passive-shutter glasses. LG showed its FPR (Film Pattern Retarder), a thin film placed over the LCD display that allows 3-D viewing with cheap, passive, polarized 3-D glasses instead of expensive and heavier active-shutter glasses.

Due for U.S. sale in April, LG sought to squash rumors that FPR is not full-resolution 3-D. Each eye only receives 540 lines, instead of the usual 1080, but LG said it’s been certified full-HD because both eyes get a total of 1080 lines.