We’re starting to see several retail websites and a few in-store displays promoting new “3D-ready" TVs. If you’re anything like us, you’ve probably wondering what exactly makes a TV 3D-ready, and how these sets are different from conventional HDTVs.
Adding to the possible confusion is the fact that there's not yet a standardized definition of what constitutes a 3D-ready TV, or uniform terminology or nomenclature to describe them.
In our recent conversations with executives from Panasonic and Samsung, it became obvious that there are basic features that all 3D TVs will have. Here are some of the common features you can expect to see on a 3D TV:
- HDMI 1.4. All 3D TVs will have HDMI 1.4 inputs, the latest version of the interface that was designed, in part, to handle the greater bandwidth and protocol controls required for 3D. The greater bandwidth is needed because the new 3D Blu-ray specification calls for players to present full 1080p resolution images to each eye, basically doubling the amount of material. HDMI 1.4 also provides the input/output protocols that let 3D displays and source components, such as Blu-ray players, communicate with each other. Some 3D-ready TVs already on the market will be able to handle 3D content via an HDMI 1.3 input, but they'll only be able to display it at half resolution. (We’ll be doing a separate blog on 3D resolution shortly.)
- 3D detection circuitry. All 3D-enabled TVs have to be able to detect a “flag” in the video bitstream that identifies it as 3D content. This circuitry then shifts the TV into its “3D mode” so the two different perspectives required for 3D can be displayed. In addition, most 3D-ready TVs will automatically adjust the TV’s settings—boosting brightness, for example, to compensate for the dimming that occurs when you use 3D shutter glasses—for optimal performance with 3D content.
- An infrared (IR) emitter. Most, but not all, TVs will likely come with an IR emitter built into the set's bezel. This emitter, or transmitter, is what communicates with the 3D shutter glasses to properly sync the glasses to the TV display, so that each eye receives its proper image but not the other. Some companies may not build the emitter into the TV, but provide it as an add-on device, or as an option packaged with the 3D glasses.
- More powerful processors, more memory. Most 3D-ready TVs will have more powerful microprocessors and built-in memory than standard sets, since they’re displaying twice as many video frames. In addition, sets that can convert 2D content to 3D on the fly–such as those announced by Samsung and Toshiba—will need even faster processors to handle the conversion algorithms that generate the effect.
- New remote controls: We expect that most new 3D-ready TVs will come with remote controls with dedicated buttons that will allow you to choose between 2D or 3D settings. Also, we imagine that there will be 3D presets added to the TV’s menu options, along with the ability to tweak key picture attributes when the TV is in the 3D mode.
Because LCD and plasma TVs produce images in a fundamentally different manner—plasma is an emissive technology that generates light, whereas LCD is a transmissive technology that requires a backlight—there will also be some features unique to each type of display. For example, 3D-ready LCD TVs will have 240Hz panels, as well as LED backlights. In 3D mode, a 240Hz panel provides two alternating images at 120 frames per second to each eye. In much the same way a faster frame rate can minimize motion blur, this technology can help reduce crosstalk, or ghosting, that can occur in sets with lower frame rates by reducing the duration that each individual image remains onscreen. LED backlights can provide better brightness uniformity across the panel, and can be flashed on and off more easily and quickly than a standard CCFL backlight.
Although plasma TV’s fast refresh rates mean they aren’t typically bothered by ghosting, plasma manufacturers have developed new phosphors and switching circuitry that can release the image even faster. And Panasonic tells us that it's adjusted the plasma gas mixture slightly to improve performance and power efficiency while maintaining image brightness.
As I mentioned in an earlier 3D post, we're working to get some of these 3D TVs in our labs for testing, so check back soon for our First Look on one of these sets. And let us know whether you're considering a 3D TV purchase this year, or whether you're going to wait it out a bit longer.
–James K. Willcox
