July 16th, 2007
Samsung adds 3D technology to its High Definition DLP TV
What do you get when you mix Digital Light Projection (DLP), Hi-Definition TV, and 3-Dimensional (3D) stereoscopic technology? You get the 3D HD DLP television that Samsung was showing off at its gadgetfest in NYC last week. While at that gadgetfest, I spotted some cool consumer technology and couldn’t leave the building without finding out more.
This TV, which uses DLP-based rear projection and ranging in price from $1499 to $4500 (depending on which size TV you go for), caught my eye (literally and figuratively for a couple of reasons).
First, to understand what’s special about the TV’s internals, you need to know a thing or two about light, video, the human eye, and display refresh rates. If I turn a flashlight on and off at you 30 times per second (30 times on, 30 times off in one second), it will appear to you as though the light was never turned off (and both eyes are looking at the same light). One reason we often hear about video operating at 30 frames per second (”fps”, the NTSC “broadcast” standard for video) is that 30 fps does an excellent job of emulating what we normally see in real life. Even 25 fps (known as the PAL standard, the European equivalent of NTSC) is pretty good. Some of the better video cameras can be toggled to record at 30 fps or 24 fps. At 24 fps, you start to get a cinematic quality to video where the on/off cycles are frequent enough to make the human eye think it’s seeing fluid video, but infrequent enough to give it that slow motion-like cinematic quality that you see in a lot of movies.
Most displays use something called interlaced video. In layman’s terms, imagine the display (or TV) has bunch of horizontal lines of light stacked top of each other, each one stretching from the left edge of the display to the right edge. Now imagine each line is numbered in sequential order. To produce 30 frames per second of video (technically, it’s 29.97 fps), one full frame is produced every 1/30th of a second. But in order to produce that one full frame, half of it (just the odd-numbered horizontal lines) are displayed or “refreshed” during one half of that 1/30th of a second (in other words, in 1/60th of a second) and the even-numbered lines are refreshed during the other 1/60th of a second. Each of the two full collections of lines — one the odd, the other the even — are called fields and when you have fields of odd and even numbered lines like that, one refreshing before the other, those fields are said to be interlaced. Thus, every frame of NTSC video that takes up 1/30th of a second is made up of two fields. They’re interlaced and each takes 1/60th of a second to refresh. Finally, for a new field to be refreshed every 1/60th of a second, most NTSC displays have a 60 Hz refresh rate.
Why does this matter to Samsung’s new 3D HDTV? 3D video actually delivers two separate streams of video; one to the left eye, the other to the right. Particularly in the case of HD video where users have high expectations of the final image, Samsung re-engineered its HD DLP TV to deliver 30 fps video to each eye (this requires stereoscopic 3D glasses in order to work). Essentially, that means a total of 60 fps. Mathematically though, it’s impossible to deliver 60 frames of interlaced video per second with a refresh rate of 60 Hz. So, what did Samsung do? It increased the refresh rate of its HD DLP TV to 120 Hz. As you’ll see in the video above, even though it’s only available in Samsung’s DLP offerings, Samsung plans to bring the 3D technology to its LCD and Plasma displays as well.
One other important point: to use the 3D technology, you need a PC with a DVI card and a software package from Samsung that takes any 2D video and converts it into 3D. Because there’s nothing like an NTSC standard for broadcast 3D, it remains to be scene if Samsung’s technology will every work with such a standard, if it emerges.
