Incompatible Glasses Could Slow Adoption of 3-D in the Home
One of the negatives of 3-D TV is that viewers must always wear special glasses to view the three-dimensional effect. But one “gotcha” that most viewers don’t know yet is that virtually all of the glasses being packaged with early 3-D TV sets are proprietary to the manufacturer’s brand. That means 3-D glasses sold by Samsung won’t work with Panasonic, Sony or other set brands. Forget bringing your 3-D glasses to a viewing party for a sporting event at the home of a friend using a different kind of 3-D display.
The cheap, polarized spectacles required to view 3-D in movie theaters won’t work at home, either. Most of the new 3-D receivers require “active-shutter” glasses that have to electronically synchronize with the TV set. The 3-D screens flash rapidly alternating images for the left and right eye. The glasses open and close shutters over each eye so the eyes see only the image intended for it. This slight difference in perspective is what gives the illusion of stereoscopic vision.
There are several reasons the glasses are incompatible. A major one is the way the signal is emitted from the TV set and what information is carried within that signal. TV sets were designed to “talk” only to their own 3-D glasses. Projectors typically use a flash of white light that bounces off the screen into the glasses. A few manufacturers link their LCDs with the glasses via radio technology, such as Bluetooth. Most LCD and plasma makers use infrared signals. But even they aren’t incompatible, much as infrared remote controls won’t work with different brands of TVs. Manufacturers also use different protocols to ensure fidelity and timing with their glasses. And, of course, each manufacturer thinks it has embraced the best design approach.
The industry knows it must have compatible glasses if there’s a chance of long-term success. Talks are already underway to produce a standard set of glasses that will work with all brands of TV sets. The most optimistic hope for a working standard is next year. Pessimists think it will never happen — in the same way RAW camera formats still differ from model to model with each brand of DSLR camera.
A couple of companies, however, are already rising to the challenge. XpanD, a European manufacturer that makes active-shutter glasses for movie theaters as well as 3-D glasses for Panasonic and Vizio TV sets, is developing universal glasses that will work across manufacturer lines, much like universal remotes can work with different gear.
The first-generation glasses, which work only with sets using infrared, are due in June at a price of about $125. Those glasses will sense the infrared signal being sent; however, they won’t work with sets that use Bluetooth or projectors that use white light. Truly universal glasses will come later, perhaps by Christmas. But they are estimated to cost more than $300 a pair.
Another company, Gunnar Optiks, which makes glasses that reduce eyestrain induced by staring at a computer screen all day, also said it plans to make universal 3-D glasses. Its technology, however, has not yet been determined.
In the meantime, 3-D TV is starting out like many other nascent technologies — not quite ready for prime time. It’s a question of time, and sales, as to whether compatible glasses will ever see the light of day.
By Michael Grotticelli, Broadcast Engineering
