COLUMN: Plasma vs. LCD

Today is Valentines Day and I am talking about television sets. “Typical” as my wife would say, but I’m sure it’s in a loving and caring way. At least I hope it is, as I don’t much feel like sleeping on the sofa.

Last week I talked a bit about what to look for in a HDTV. We’ve covered the resolution, contrast ratio, and refresh rate thus far. Today we’ll be looking into Plasma and LCDs. Both are great technologies and offer their merits, but use drastically different means to achieve them.

The way Plasma sets work is cool. Inside the TV are tiny cells filled with noble gases. If you recall your high school chemistry you’ll know these are helium, neon, argon, krypton and xenon. In fact, the mixture works in much the same way a neon sign does. Apply some current and the gas inside lights up in various colors. Scale this down many, many times and you’ll have a pixel inside a Plasma television set.

Plasmas were infamous in the past for what was called “burn in.” This occurred when you left a still image on the screen for too long. After that happened, there was always a ghost of that image on the screen, regardless of what you were watching. Thankfully, this problem is mostly solved. That is not to say you should leave for a weeks vacation with a movie paused and the television on, but anything short of that should be fine.

Plasma TVs are quite a bit heavier and more power hungry than their LCD counterparts, but they are getting thinner and lighter. Their contrast ratio cannot be beat by an LCD. In fact, if you are only looking for a 720p set and all you care about is image quality, you want a Plasma. Naturally, I’m assuming that you plan on staying in the South for awhile. Plasmas have a known issue with altitudes above 6,000 feet called the “Denver Problem.” However, living near sea level is perfect for them.

LCDs (liquid crystal displays) are a bit easier to understand than Plasma televisions. They consist of two major components, a liquid crystal gel that sits in front of a backlight. This backlight is usually of two types, either a CCFL, which stands for “compact florescent” like those energy saving light bulbs, and LED, which is a light emitting diode. It provides the illumination to allow the liquid crystal gel to be seen.

As a rule, cheaper LCDs have a problem with motion response (low refresh rate) as well as contrast ratio. The middle of the road and more expensive LCD models tend to break about even with their Plasma counterparts. In the next few years however, OLED LCDs will become cheaper and will have a real advantage. OLED stands for “organic light emitting diode” and can turn individual pixels on and off like a Plasma, but uses less energy and is lighter, like an LCD. It’s the best of both worlds. OLED displays are much too expensive for mass marketing right now, but time and research will change that.

— Senior Production Coordinator Matthew Broughton is taking the “ech” out of tech. E-mail him at mbroughton@florencenews.com.