South Carolina ETV
Digital TV 101: Types of TVs
In this segment, we'll talk about those new numbers assigned to every TV set. 480, 720 and 1080, otherwise known as screen resolution. Before you panic, you should know you've probably made this choice before without knowing it - if you've ever bought bed sheets.
In this segment, we're going to talk about types of TVs: two you've probably seen already, two you'll be seeing more of, and one old favorite.
First, you don't need one of those thin sets you hang on walls to have digital TV. Our old friend, the cathode ray tube, around since 1897, has been re-tooled for widescreen and digital and HDTV. The ever-reliable CRT, the one you've always had, is still available in digital format.
Now, to the two kinds of new TVs you've most likely already seen:
A plasma TV uses neon and xenon gas inside a glass panel to produce images. Plasmas are known for excellent picture quality and better viewing from side angles. The downside can be "burn-in" which is when you leave the TV on one channel all the time and one image -- a news ticker or a station logo in the corner -- becomes a faint, ghost-like image on your screen no matter what channel you're on. For most viewers and most normal viewing patterns, burn-in isn't much of an issue. FYI -- the first hundred hours of use are when burn-in is most likely to occur. On newer models, burn-in is temporary -- if you just switch to other channels for a while, the ghost image will go away. Plasma also uses the most energy of the new kinds of TV sets -- a large screen can add up to $100 a year to your electric bill. A full entertainment system can double that.
The second most familar of the new TVs is LCD. LCD stands for Liquid Crystal Display. LCD TVs are known for sharp pictures, deep blacks and for being less expensive, but they can be harder to view from a side angle. Burn-in is not an issue with LCD displays except in extreme cases -- leaving a TV on one channel 24/7 for days on end, for example. LCDs might also have a bit too much blur for serious gamers. Usually LCD screens are less reflective, so if light from windows is an issue in your home, you may want to take that into consideration.
Now to some less well-known, but quickly advancing technologies. These two up and comers are projection systems, either from a projector mounted on your ceiling or the new thin rear-projection TVs.
There's a new kind of projection TV that uses DLP, digital light projection. The amazing DLP chip contains up to 2 million hinged mounted micro-mirrors that project a picture onto a screen, either from the front or behind. This is the same technology being used in the new filmless movie theatres. DLP projectors take up to a minute to for the light inside to warm up or cool down. They're known for a good uniform picture, though when used in rear-projection sets, viewing from the side may not be a sharp as from directly in front. They also sometimes exhibit a rainbow effect across the screen. You've probably paid good money to see a DLP in action at the local digital movie theatre, and the visual result is indeed eye-popping. They are also the first sets to promise 3D movies and games -- in the future.
Another video projector technology is LCoS - Liquid Crystal on Silicon, the most expensive of the pack, with a very smooth picture but limited contrast. Early models have a shorter lamp life, relatively speaking. But for many videophiles, the word "elegant" gets used with this technology. Others find it's not sharp enough. It's projector is not compact. It's a new technology, keep your eye on it. It has many fans with large wallets.
As always, different makes and models offer different options, and while our advice is true for most types, it's not true for all. Buyer beware -- stand in front, stand to the sides, look up at each set and look down at it -- and, ultimately, trust your own eyes as to which TV suits you best
For more information about ETV's Digital Television Services, contact:
Hap Griffin, Vice President, Engineering
Voice: (803) 737-3500
E-mail: hgriffin@scetv.org
ETV Administration Building
1101 George Rogers Boulevard
Columbia, SC 29201-4761
Phone: 803-737-3545
ETV Telecommunications Center
1041 George Rogers Boulevard
Columbia, SC 29201
Phone: 803-737-9959