

To absolutely no-one’s surprise, 3DTV was the dominant theme of this year’s Consumer Electronics Show in January. After all, 3DTV activities simmered all year long in 2009, with various CES and CEDIA demonstrations, and predictions from major industry executives that real 3DTV product would indeed ship in 2010. And, that’s certainly the case, with most (but not all) of the major HDTV set-makers making announcements at the 2010 CES about forthcoming 3D products that will ship starting in the spring and summer, including 3DTV flat panels, projectors and Blu-ray players.
At posting time, however, suggested retail pricing for most of the product debuted at the show remains cloudy. That’s not at all unusual, though, since it’s normal for vendors to withhold pricing until closer to a product’s release date, which in many cases will be a few months after the show, with most announced models being available by summertime and early fall.
And, despite the announcement at the end of 2009 that the Blu-ray Disc Association had finalized a 3DTV specification, much remains out of focus, if you will. To see where 3DTV stands now, we first need a quick review to understand where the technology has come from.
The simplest 3D theater system has viewers wearing spectacles with different color gel filters for each eye, usually red and cyan (but sometimes with other color combos such as green/magenta or yellow/blue). Without the glasses, images exhibit pronounced color ghosting effects and are almost unwatchable, while with the glasses the images become 3D, but due to the color filters in the glasses they often provide an unrealistic color palette. Anaglyphic 3D traces its origins back to a handful of 3D black and white movies released in the early 1920’s.
The three principal movie theater 3D systems are RealD, IMAX 3D, and Dolby 3D, and they utilize high resolution Digital Cinema Initiative (DCI) DLP-based projection. These systems use polarized (passive) filter glasses to achieve left eye/right eye image differentiation, which provides the stereoscopic 3D imaging effect. Dolby’s system adds slightly different RGB color differentiation filters for each eye (a concept originally developed by Infitec, an offshoot of DaimlerChrysler), which improves what’s called the “extinction ratio”; that is, the ability of the 3D system to provide increased left/right image differentiation for improved 3D effects. The IMAX 3D system also relies on a modest amount of anaglyphic-type color differentiation in addition to the polarizing function.
Studios and exhibitors prefer polarized 3D projection systems because the cost of passive 3D glasses is substantially less than with active shutter-type liquid crystal (LC) 3D glasses and because sanitization for re-use is also easier and less costly. What is more, with passive glasses there is no need to worry about battery life and battery replacement/recharging issues, as with active glasses.
At CES 2010, both passive (polarized) and active liquid crystal (LC) shutter-type 3D systems abounded. With active (shutter-type) 3D, the battery-powered glasses incorporate infrared sensors that detect IR timing synchronization pulses from the display, and alternate the individual LC lenses between translucent and opaque, according to the timing of the image. Both types do attenuate picture brightness to some degree in the process, however.

Active 3D LC shutter-based systems generally are considered superior to passive 3D polarized methods, due to increased left/right extinction ratio and have fewer deleterious artifacts. For these reasons, most major TV vendors, including Panasonic, Sony, Samsung and Toshiba, have chosen active shutter systems. 3D cinema vendor RealD announced partnerships with these firms at the show to provide active LC shutter glasses technology, and in some cases, the glasses themselves.
Comments
"Active 3D LC shutter-based systems generally are considered superior to passive 3D polarized methods.... For these reasons, most major TV vendors, ...have chosen active shutter systems"
That is not true! TV vendors came up with that because
This is the fastest path for them to brag about '3D display' without any extra R&D not because LCD shutter glasses are superior or anything close to that! Come on!
Right, also active shutter glasses can give headache and also after using it for an hour or so.
Active glasses use infra-red signals from a transmitter to operate properley. When watching TV using active shutter glass, should not turn / move head and should seat like a statue.
TV technology is not advanced enough, to use polized glasses. TV vendors won't say, polarized glasses are better and easy to use! I know some people may like to charge the batteries of active shutter glasses time to time to watch their fav programme.
Thanks