Your tax return is in the mail and now you’re finally ready to ditch your tiny plebeian TV you’ve been keeping and join the ranks of the NCAA Final Four Party Elite with a big screen HDTV. Problem is, when you walk into the showroom, you're faced with an overwhelming array of big screens to choose from and a bombardment of one acronym after another. DLP, LCD, LCOS? How is anyone supposed to narrow down their list of candidates? This article.
Once you're done reading this article, you'll hopefully be able to figure out which TV technology is right for you and will understand the basics of big screen TVs. That’ll help keep your list of TVs to shop for short. As a disclaimer, in order to make this article accessible to the widest audience, this isn’t a comprehensive or technical buyer’s guide – this one is for the novices.
TV Technology 101
All TVs can be grouped into one of two categories: those that "burn-in" and those that do not. TVs in the first category uses electricity to blast tiny particles called phosphors that glow when energized. Over time, the phosphors wear out and dim. If the phosphors on the screen all wear out evenly, it's not a problem because the changes are gradual and our eye and brain will compensate. "Burn-in" occurs when the phosphors in one part of the screen wears out prematurely.
This occurs with static images such as a TV station logo or a video game health status bar. The result is a "burned-in ghost image" – you'll see that shadow of a TV station logo on everything you watch. Another source of burn-in comes from watching non-widescreen TV shows (4:3 aspect ratio) on a widescreen TV; if the edges are always black, they will look brighter than the center of the screen.
Regular TVs and computer monitors are in this category; an electron gun (a cathode ray gun) blasts phosphors on a glass screen (the tube). CRT rear projection TVs and plasma screens also use variants of this technology. A CRT rear projector can be thought of as being made up of 7 to 9" regular TVs with a picture so bright, that the image is projected onto a screen. Plasma screens work somewhat similarly except the phosphors are energized through a different approach.
A key point is that since both CRT rear projection TVs and plasma screens more intensely energize the phosphors than a typical CRT TV, the phosphors wear out more quickly and thus more easily burn in than your classic TV or computer monitor.
The second type of TV uses a transparent or reflective colored filter and a bright light bulb. Think of it as an overhead or slide projector. There is no burn-in with this approach because the light source shines evenly across the screen. For projection TVs, a high-intensity discharge bulb similar to a luxury car headlamp or hydroponic grow light is used. These light bulbs burn out after 2000 to 5000 hours (it varies by manufacturer), but you can easily replace the bulb for about $200-$300. This is the approach used by LCD, DLP, and LCoS projection televisions. LCD flat panels also fit into this category, with the exception that it is a row of cold cathode fluorescent bulbs that light up the screen.